Title Science and Technology Indonesia e-ISSN:2580-4391 p-ISSN:2580-4405 Vol. 6, No. 2, April 2021 Research Paper Synthesis of Titanium Dioxide Nanotubes with Different N-Containing Ligands via Hydrothermal Method Cheng Yee Leong1, Ye Shen Lo1, Pei Wen Koh2, Siew Ling Lee1,3* 1Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310 Johor Bahru, Malaysia2CSC Screen Process Supplies Sdn Bhd, 14, Jalan Bertam 5, Taman Daya, 81100 Johor Bahru, Johor, Malaysia3Centre for Sustainable Nanomaterials, Ibnu Sina Institute for Scientific and Industrial Research, Universiti Teknologi Malaysia (UTM), 81300 Johor Bahru, Malaysia *Corresponding author: lsling@utm.my AbstractTitanium dioxide (TiO2) nanotubes (TNT) were successfully synthesized using different N-containing ligands via hydrothermalmethod. Methylamine, ethylenediamine and diethylenetriamine with different Ti/ligand molar ratios (1:1, 1:3, 1:5 and 1:8) wereprepared. As-synthesized TiO2 without N-containing ligands were also prepared for comparison purpose. The X-Ray Diffractionpatterns confirmed the presence of anatase phase of TiO2 in all the synthesized samples whereas the presence of sodium titanatewas only detected in the samples containing N-containing ligands. The Transmission Electron Microscopy images also showed thatthe N-containing ligands promoted the formation of nanotubes in the anatase TiO2. Based on the Tauc Plot, the band gap energyof anatase TiO2 was shifted with the addition of methylamine, ethylenediamine and diethylenetriamine. The photoluminescencespectra also showed that with the addition of sufficient amount of N-containing ligands, the intensity of photoluminescencespectrum decreased, suggesting formation of more nanotube and reduction of electron hole recombination rate. The photocatalyticperformance of all synthesized samples was determined through photodegradation of Congo red under UV light for 6 hours. Theresults suggested that among the synthesized materials, the sample which contained diethylenetriamine with molar ratio of 5gave the highest photocatalytic activity of 76.71% which could be attributed to successful formation of nanotube, its higher surfacerate reaction and low electron hole recombination. Diethylenetriamine showed higher efficiency in assisting the formation of TiO2nanotubes compared to methylamine and ethylenediamine. KeywordsTitanium dioxide nanotube, N-containing ligands, photocatalyst, hydrothermal, Congo red Received: 20 February 2021, Accepted: 23 March 2021 https://doi.org/10.26554/sti.2021.6.2.67-73 1. INTRODUCTION Titanium dioxide (TiO2) nanoparticles is examined as an inert and safe material and has been used in many applications such as pigments, sunscreen and coloring. Nonetheless, TiO2 only absorbs ultraviolet light due to its large band gap energy of 3.2 eV. Therefore, it is desirable to reduce the band gap of anatase TiO2 to be active under visible region. Several approaches had been used including doping of metal and non-metal as well as modication of the surfaces (Koh et al., 2017; Ooi et al., 2020; Ooi et al., 2016; Lee et al., 2016). Doping of TiO2 with metals has a major drawback that the photocatalytic activity of metal doped TiO2 could be inuenced by dopant concentration. While, for the doping of TiO2 with non-metals, the doping into the lattice of TiO2 usually resulted in the for- mation of oxygen vacancies in the bulk which deteriorate the visible light photocatalysis eciency in industrial applications (Dong et al., 2011; Li et al., 2008). As an alternative, the mor- phologies of TiO2 photocatalysts has been intensively explored to improve its performance as a photocatalyst. Compared to zero-dimensional and two-dimensional nanostructures, more attention has been paid to one-dimensional TiO2 nanostruc- tures which include nanowire, nanorod and nanotube due to its high aspect ratio, large specic surface area and excellent ionic charge transport property (Lee et al., 2014). Hydrothermal synthesis is a facile and preferable route for the synthesis of TiO2 nanotubes since the products prepared by this method have well crystalline phase, which benets to ther- mal stabilityof the nanosized materials. Even so, traditional hy- drothermal synthesis of TiO2 nanotubes often requires highly concentrated alkali such as 10 to 12 M of KOH or NaOH (Kasuga et al., 1998). In our research group’s previous study, it showed that the synthesis of TiO2 nanotubes could be done in the presence of low concentration of alkali with the assistance https://crossmark.crossref.org/dialog/?doi=10.26554/sti.2021.6.2.67-73&domain=pdf https://doi.org/10.26554/sti.2021.6.2.67-73 Leong et. al. Science and Technology Indonesia, 6 (2021) 67-73 of N-ligand (Leong et al., 2020). In that study, methylamine was used as the N-ligand, allowing the binding between the N atom of methylamine with the Ti +4 of the titanate layer, hence, assisting the nanosheet to curl up, forming TiO2 nan- otube (Leong et al., 2020). Other than methylamine, both the ethylenediamine and diethylenetriamine (DETA) are also the N-ligands. More N atoms can be found in these two N-ligands as compared to methylamine. Since the N atom plays a major role in assisting the TiO2 nanotubes formation as proven in the previous study, it is expected that ethylenediamine and DETA work better than methylamine. As such, this current study is aimed to investigate the eect of dierent N-containing ligands on the formation of TiO2. An attempt was made to synthe- size TiO2 nanotubes with dierent N-containing ligands via hydrothermal method in a xed hydrothermal condition. 2. EXPERIMENTAL SECTION 2.1 Materials Anatase TiO2 powder (Sigma Aldrich, ≥ 99.0%), methylamine hydrochloride (Sigma Aldrich, ≥ 98.0%), ethylenediamine (Merck, ≥ 99.0%),diethylenetriamine(Merck, ≥ 98.0%), sodium hydroxide (Merck, ≥ 99.0%), Congo red. 2.2 Methods In a typical synthesis, inside a Teon bottle, 0.5 g of anatase TiO2 powderwas mixed with mixture of 70 mLof 7 M sodium hydroxide and 0.419 mL ethylenediamine. The molar ratio of Ti to ethylenediamine was 1:1. The mixture was stirrer vig- orously (1000 rpm) for 1 h. After that, the Teon bottle was transferred into stainless-steel autoclave and hydrothermally treated at 130◦C for 24 h. The obtained white precipitate was washed with 0.01 M sulfuric acid and double distilled water until pH 7 before drying at 60◦C overnight. Samples with other Ti to ethylenediamine molar ratio (1:3, 1:5, 1:8) was prepared with the same conditions. Samples were also prepared with exactly the same method and conditions using methylamine and diethylenetriamine as the ligand in replace- ment of ethylenediamine. For comparison purpose, as-TiO2 was prepared with the same conditions without addition of ethylenediamine. Samples was labelled as xY-TNT where x is the molarratio of ligand (1,3,5,8), Yis the ligand (methylamine, ethylenediamine, diethylenetriamine) and TNT is the titania nanotube. The phases and crystallinity of the samples were examined with X-ray Diractometer (XRD) (Bruker Advance D8) with Cu K𝛼 irradiation (_ = 0.15406 nm, 40 KV, 40 mA). Sam- ples were scanned in the range 2\ = 2 – 80◦ with step size 0.05◦/s. The morphology of the selected samples was con- rmed with Transmission Electron Microscopy (TEM) (JEOL JEM-2100) operating at 200 KV. Samples were dispersed in absoluteethanolandultrasonicatedfor10minutesprior to load onto carbon coated copper grid. (Perkin Elmer Ultraviolet- visible Spectrometer Lambda 35) was used to study the optical properties of the samples. Barium sulphate was used as the reference. Fixed amount of sample (2.000 ± 0.0005 g) was put into the sample holder and was scanned in the range 200 – 800 nm. Band gap energy of the samples was obtained from Tauc plot. It is a plot of (𝛼ha)2 against ha where 𝛼 is the absorbance, h is the Planck constant and a is the velocity of light. Photolu- minescence (JASCO, FP-8500) with an excitation of 344 nm was used to study the rate of electron-hole recombination of the samples. Photocatalytic testing was carried out using 50 mL 15 ppm Congo red and 0.01 g samples and irradiated under UV for 6 h. Prior to reaction, adsorption was carried out to ensure the decreased of the concentration was attributed solely to photodegradation. 3. RESULTS AND DISCUSSION 3.1 Structural Properties Figure 1 illustrated the XRD patterns of as-synthesized TiO2 and samples dierent N-ligands molar ratio. The XRD pat- tern of as-synthesized TiO2 pattern conrmed the presence of anatase phase (JCPDS 21-1272) in which the peaks can be found at 2\ values of 24.8◦, 37.3◦, 47.6◦, 53.5◦, 55.1◦ and 62.2◦ that corresponded to (101), (004), (200), (105), (211) and (204) crystal planes respectively. The peak positions were consistent with the standard diraction pattern of anatase TiO2 with no other crystalline phase observed. A broad peak was observed at 2\ values of 28◦ in the synthesized samples that containing N-ligands. The peak represented Na2Ti3O7 type of sodium titanate (JCPDS 31-1329). The presence of Na atoms can be explained when treating the raw material with aqueous NaOH solution, some Ti-O-Ti bonds were broken, and Ti-O- Na and Ti-OH bonds were formed (Kasuga et al., 1998). It was proposed that acid treatment on the sample changed the composition in the sample from sodium titanate to hydrogen titanate through an ion exchange mechanism and aected the attributes of TNTs owing to the relative amount of Na and H atoms within TNT structure (OU and LO, 2007). How- ever, there were not characteristic peak of hydrogen titanate observed in the XRD pattern. It was because the pH of the samples were washed approximately to 7 that can retard the ion exchange process so the nanotubes mostly retain their sodium titanate composition (Weng et al., 2006). 3.2 Morphology of the Samples Figure 2 showed the TEM and HRTEM images of the selected samples. A mixture of unreacted nanoparticles of TiO2 pow- ders and TiO2 nanotubes was observed in Figure 2 (e) and (f). The nanoparticles of TiO2 in anatase had a spherical morphol- ogy. From the distance between the adjacent lattice fringes, the nanoparticles showed lattice spacing of d = 0.35 nm for the (101) plane of the anatase phase which was consistent with the XRD results. Figure 2 (a), (b), (c) and (d) showed the TEM micrograph of the samples that contained N-ligands. It can be observed that the samples both contained TiO2 nanotubes that overlap each other and had constant diameter of 10 - 15 nm. The interspacing between the neighboring anatase of the tube © 2021 The Authors. Page 68 of 73 Leong et. al. Science and Technology Indonesia, 6 (2021) 67-73 Table 1. Synthesis Conditions of Dierent Ligands with Dierent Ratio Ligand Ratio Volume (mL) / Temperature Duration LabelWeight used (g) (°C) (Hours) Methylamine 1:01 0.0972 g 130 24 1 MT TNT Methylamine 1:03 0.5833 g 130 24 3 MT TNT Methylamine 1:05 0.9721 g 130 24 5 MT TNT Methylamine 1:08 1.5553 g 130 24 8 MT TNT Ethylenediamine 1:01 0.4190 mL 130 24 1 ET TNT Ethylenediamine 1:03 1.2580 mL 130 24 3 ET TNT Ethylenediamine 1:05 2.0970 mL 130 24 5 ET TNT Ethylenediamine 1:08 3.3550 mL 130 24 8 ET TNT Diethylenetriamine 1:01 0.6458 mL 130 24 1 DT TNT Diethylenetriamine 1:03 1.9375 mL 130 24 3 DT TNT Diethylenetriamine 1:05 3.2290 mL 130 24 5 DT TNT Diethylenetriamine 1:08 5.1668 mL 130 24 8 DT TNT wall was determined to be about 0.24 nm which correspond for the plane (004) of anatase TiO2. Scherrer Equation was then used to calculate the crystal- lite size of as-synthesized TiO2 and samples that contained N-ligands. From the calculation, the crystallite size of as- synthesized was larger than samples that contained N-ligands. It was reported that smaller crystallite size of TiO2 with high surface area can increase the number of active surface sites and the surface charge carrier transfer rate in the photocatalytic reaction (Carrera-López and Castillo-Cervantes, 2012). The results indicated that as-synthesized TNT has crystallite size of 31.60 nm. Upon modication with either methylamine, ethylamine or diethylenetriamine surfactant, the crystallite size of the samples decreased to the range of 26.33 – 26.27 nm. This showed that the addition of these three surfactants able to reduce the crystallite size of TNT. However, comparison among the modied samples, it was noted that the amount of surfactant has insignicant eect on the crystallite size. This was because N atoms had been introduced into the lattice with- out changing the average unit cell dimension (Sathish et al., 2005). 3.3 Optical Properties Inordertostudytheeectofdiethylenetriamine ligandtowards the optical property of TiO2 NT, the synthesized samples were subjected to analysis using DR-UV-Vis spectrophotometer. The optical spectrum of the samples was depicted in Figure 3. As shown in Figure 3 (a), it had a peak located between range of 270 nm to 280 nm, which were associated with the hydrated tetrahedral Ti species that is widely recognized as the most important Ti species to provide active site for the photocatalytic activity of TiO2 (Lee et al., 2015; Xu et al., 2015). The band gap energy was determined using Tauc Plot, the addition of diethylenetriamine increased the band gap en- ergy of as-synthesized TiO2 NT from 3.2 eV to 3.25 eV, 3.27 eV, 3.29 eV and 3.31 eV for 1 DT TNT, 3 DT TNT, 5 DT TNT and 8 DT TNT respectively. Apparently, the band gap energy increased when the molar ratio of diethylenetriamine increased. it was reported that the decrease in particle size resulted in increased of band gap energy due to quantum size eect (Avinash et al., 2016). As shown in Figure 3 (b), TNT synthesized with the presence of diethylenediamine gave a sim- ilar optical spectrum when diethylenetriamine was used; there was broad peak located between range of 280 nm to 295 nm which was attributed to octahedral Ti (Lee et al., 2015). The addition of ethylenediamine decreased the band gap energy of as-synthesized TiO2 NT from 3.2 eV to 2.95 eV, 2.93 eV, 3.03 eV and 3.13 eV for 1 ET TNT, 3 ET TNT, 5 ET TNT and 8 ET TNT respectively. In general, addition of ethylamine surfactant reduced the band gap energy of as-synthesized TiO2 from UV region to visible light region. This visible light absorption could be at- tributed to the N atom of the surfactant which nitrogen was incorporated in TiO2 lattice so the localized N 2p states were positioned above the titanium dioxide valence band and the band gap became narrow (Dolat et al., 2013). As shown in Figure 3 (c), an absorption peak at 320 nm was indicated in all synthesized samples except as-synthesized TiO2 which was associated to anatase TiO2 (Xiong et al., 2017). An absorption peak at 270 nm can be found in all synthesized samples which was related to amorphous Ti (Cambloret al., 1993). It could be suggested that methylamine promoted the transformation of amorphous Ti species crystalline anatase phase of TiO2. The addition of methylamine increased the band gap energy of as- synthesized TiO2 NT from 3.2 eV to 3.37 eV, 3.41 eV, 3.35 eV and 3.27 eV for 1 MT TNT, 3 MT TNT, 5 MT TNT and 8 MT TNT respectively. There was no signicant inuence of the molar ratio of methylamine on the band gap energy of TiO2. The increase of band gap energy of samples synthesized © 2021 The Authors. Page 69 of 73 Leong et. al. Science and Technology Indonesia, 6 (2021) 67-73 Figure 1. XRD Patterns of (a) Samples with Methylamine and As-synthesized TiO2, (b) Samples with Ethylenediamine and As-synthesized TiO2, (c) Samples with Diethylenetriamine and As-synthesized TiO2 with the presence of methylamine compared to as-synthesized TiO2 TNT could be due to quantum size eect (Avinash et al., 2016). 3.4 Photoluminescence Study Photoluminescence spectroscopy was carried out to study the electron hole recombination rate. From Figure 4 (a), the in- tensity did not directly relate to the molar ratio of diethylen- etriamine. 1 DT TNT has the highest intensity while 8 DT TNThas the lowestemission intensity. Theresults implied that 1 DT TNT had the lowest electron-hole recombination rate while 8 DT TNT had the highest electron-hole recombination rate. Compare to as-synthesized TiO2, except 8 DT TNT, pres- ence of diethylenetriamine reduced the electron-hole recom- bination rate of as-synthesized TiO2 TNT which could be attributed to diethylenetriamine assisted in formation of nan- otube. It was reported that nanotube enhanced the electron trans- fer to the surface hence retard the electron-hole recombination Figure 2. TEM and HRTEM Image of (a), (b) 5 DT TNT, (c), (d) 3 MT TNT, and (e), (f) as-synthesized TiO2 rate (Sunetal.,2008). Additionofexcess surfactant (Ti: DETA = 1: 8) resulted in increasing of electron-hole recombination rate. This could be due to excess of surfactant acted as re- combination center. From Figure 4 (b), the lowest intensity of the peak was 1 ET TNT and the highest intensity of the peak was 8 ET TNT. The intensity of the peak of 1 ET TNT was lower compared to as-synthesized TiO2 could be attributed to more nanotube was formed which retarded the electron-hole recombination rate (Sun et al., 2008). On the other hand, further addition of diethylenediamine increased the emission intensity even though more nanotube was formed. A possible explanation for increased emission in- tensity could be ascribed to more electrons were excited from valance band to conduction band (Fang et al., 2015). From Figure 4 (c), there was a decrease in uorescence intensity with an increase in the amount of methylamine added to the anatase TiO2. It can be explained that the formation of more nanotube as evidence from the TEM images, reduced the electron-hole recombination rate. Alternatively, the nitrogen facilitated the separation of photo-generated electron–hole pair for the for- mation of oxygen vacancies that can inhibit the recombination of photo-generated charge to some extent (Irie et al., 2003). The intensity for 5 MT TNT was exactly the same 8 MT TNT. This indicated that the reduction in photoluminescence inten- sity had achieved saturation without further reduction. From Figure 4 (d), 3 MT TNT had the lowest intensity which indi- cated it had lowest electron hole recombination rate but it can decrease the surface reaction rate and lower the photocatalytic activity (Wojcieszak et al., 2013). 3.5 Photocatalytic Testing From Table 2, the photocatalytic activity for 5 DT TNT was higher compared to as-synthesized TiO2. It can be explained basedontheTEMmicrographs inwhichmoreTiO2 nanotubes © 2021 The Authors. Page 70 of 73 Leong et. al. Science and Technology Indonesia, 6 (2021) 67-73 Table 2. Photocatalytic Activities of Samples Prepared with and without Diethylenetriamine Temperature Duration Sample Q1 (ppm) Q2 (ppm) Photocatalytic (◦C) (hours) Eciency (%) 130 24 As-synthesized TiO2 12.9 5.91 54.2 130 24 1 DT TNT 12.76 5.16 59.6 130 24 3 DT TNT 13.26 4.94 62.7 130 24 5 DT TNT 13.29 3.1 76.7 130 24 8 DT TNT 12.98 4.79 63.1 Table 3. Photocatalytic Activities of Samples Prepared with and without Ethylenediamine Temperature Duration Sample Q1 (ppm) Q2 (ppm) Photocatalytic (◦C) (hours) Eciency (%) 130 24 As-synthesized TiO2 12.9 5.91 54.2 130 24 1 ET TNT 13.68 6.87 49.8 130 24 3 ET TNT 13.43 5.96 55.6 130 24 5 ET TNT 12.62 3.61 71.4 130 24 8 ET TNT 12.16 6.9 43.2 were produced with the addition of diethylenetriamine com- pared to as-synthesized TiO2. Diethylenetriamine might assist the scrolling of the intermediate nanosheet to form nanotube in which higher degree of nanotubes formation enhanced the photocatalytic activity of TiO2. Besides, the results showed that the photocatalytic eciency increased when the molar ratio of diethylenetriamine increased until a certain extent. This is because appropriate amount of di- ethylenetriamine and appropriate temperature were benecial to increase excited electrons, and thus improve the photocat- alytic activity. Even though 5 DT TNT did not have the lowest electron-hole recombination rate (it has the second lowest emis- sion intensity as shown in the photoluminescence spectra in Figure 4 (a)), but it has the best photocatalytic activity. This could be because it had faster surface reaction rate than the recombination rate that resulted in a net increase of photo- catalytic eciency. It was reported that both recombination rate and surface reaction rate were the factors to determine the photocatalytic activity. FromTable3, subsequent increaseofmolarratioofethylene- diamine from 1 to 5, the photocatalytic activity of TiO2 nan- otubes was increased. 5 ETTNThas the highest photocatalytic eciency of 71.4%. Even though 5 ET TNT has relatively higher emission intensity compared to 1 ET TNT and 3 ET TNT,but theobtainedphotocatalyticeciencywashigherthan the later. The reason could be the surface reaction rate at 5 ET NT was very high which overcome the eect of electron-hole recombination and resulted in a better activity. On the other hand, the photocatalytic activity decreased after the ethylene- diamine molar ratio used was higher than 5. This could be deduced that addition of excess ethylenediamine acted as re- combination centre and the fate of electron-hole recombina- tion rate was more prevailed. From Table 4, samples contained methylamine had higher photocatalytic activity compared to as-synthesized TiO2 and 3 MT TNT had the highest photo- catalytic eciency. FromtheTEMmicrograph, thecrystallitesizeofas-synthesized TiO2 was larger than 3 MT TNT. It was reported that the av- erage diusion path length of charge carrier from the bulk to the surface became longer in a bigger TiO2, which will result in deep trapping of charge carriers, leading to lower photocat- alytic activity. In addition, reduction in crystallite size which resulted in larger surface area can increase the available surface- active sites and consequently resulting in higher photocatalytic eciency. Therefore, it was believed that 3 MT TNT has the highest photocatalytic activity was attributed smaller crystallite size that resulted in faster charge transfer and more surface- active site. 4. CONCLUSIONS The synthesis of TiO2 nanotubes were successfully performed via hydrothermal method using of dierent N ligands. All the samples consisted of white powder which indicated that the addition of N ligands did not aect the color of TiO2. The samples were characterized successfully to study their physi- cal and chemical properties. The XRD analysis indicated the presence of anatase TiO2 and sodium titanate in the samples that contained N ligands. From the TEM analysis, more nan- otubes were formed in 3 MT TNT and 5 DT TNT compared to as-synthesized TiO2. From the Tauc plots, there was a shift- ing in the band gap energy of the samples that contained N ligands. Photoluminescence spectrum also showed there was a decrease in the intensity from the spectrum with the addition of certain N ligand until certain extent which can relate to the © 2021 The Authors. Page 71 of 73 Leong et. al. Science and Technology Indonesia, 6 (2021) 67-73 Table 4. Photocatalytic Activities of Samples Prepared with and without Methylamine Temperature Duration Sample Q1 (ppm) Q2 (ppm) Photocatalytic (◦C) (hours) Eciency (%) 130 24 As-synthesized TiO2 12.9 5.91 54.2 130 24 1 MT TNT 13.07 4.16 68.2 130 24 3 MT TNT 12.82 3.93 69.4 130 24 5 MT TNT 13.27 5.24 60.5 130 24 8 MT TNT 12.67 5.26 58.45 Figure 3. DR-UV-Vis Spectra of (a) Methylamine, (b) Ethylenediamine, and (c) Diethylenetriamine electron hole recombination rate. The photodegradation of Congo red also gave result that samples with N ligands with optimum molar ratio had higher photocatalytic activity than as-synthesized TiO2. The photocatalytic eciency for each of the synthesized samples was determined through photodegra- dation of Congo red under dark condition and UV irradiation for 6 hours. From the results, 5 DT TNT (76.7%), 5 ET TNT (71.4%) and 3 MT TNT (69.4%) showed the highest photocatalytic eciency among their series and had higher photocatalytic eciency than as-synthesized TiO2 (54.2%). In conclusion, titanium dioxide nanotube was successfully synthe- sized via hydrothermal method in this study. 5 DT TNT was the best photocatalyst in the photodegradation of Congo red with photocatalytic activity of 76.71%. Methylamine, ethylene- Figure 4. Photoluminescence Spectra of Titania Nanotube Synthesized with (a) Diethylenetriamine, (b) Ethylenediamine, (c) Methylamine, and (d) Comparison of Selected Samples with Highest Activities diamine and diethylenetriamine played an important role to assist in the formation TiO2 nanotube. Diethylenetriamine showed higher eciency in assisting the formation of TiO2 nanotubes compared to methylamine and ethylenediamine. 5. ACKNOWLEDGEMENT Authors are whole-heartedly appreciated the nancial support given by Ministry of Higher Education, Malaysia (MOHE) for the Fundamental Research Grant Scheme (Reference no.: FRGS/ 1/2019/STG07/UTM/02/12). REFERENCES Avinash, B. S., V. S. Chaturmukha, H. S. Jayanna, C. S. Naveen, M. P. Rajeeva, B. M. Harish, S. Suresh, and A. R. Lamani (2016). Eect of particle size on band gap and DC electrical conductivityof TiO2 nanomaterial. AIPConference Proceedings, 1728; 20426 Camblor, M., A. Corma, and J. Pérez-Pariente (1993). Syn- thesis of titanoaluminosilicates isomorphous to zeolite Beta, active as oxidation catalysts. Zeolites, 13(2); 82–87 © 2021 The Authors. Page 72 of 73 Leong et. al. Science and Technology Indonesia, 6 (2021) 67-73 Carrera-López, R. and S. Castillo-Cervantes (2012). Eect of the phase composition and crystallite size of sol-gel TiO2 nanoparticles on the acetaldehyde photodecomposition. Su- percies y vacío, 25(2); 82–87 Dolat, D., S. Mozia, B. Ohtani, and A. Morawski (2013). Ni- trogen, iron-single modied (N-TiO2, Fe-TiO2) and co- modied (Fe, N-TiO2) rutile titanium dioxide as visible- light active photocatalysts. Chemical engineering journal, 225; 358–364 Dong, F., S. Guo, H. Wang, X. Li, and Z. Wu (2011). En- hancement of the Visible Light Photocatalytic Activity of C-Doped TiO2Nanomaterials Prepared by a Green Syn- theticApproach. TheJournalofPhysicalChemistryC,115(27); 13285–13292 Fang, Q., J. Tang, H. Zou, T. Cai, and Q. Deng (2015). Prepa- ration of N-Doped Mesoporous TiO2 Using Nitromethane as Nitrogen Source and Their High Photocatalytic Perfor- mance. Synthesis and Reactivity in Inorganic, Metal-Organic, and Nano-Metal Chemistry, 46(5); 766–774 Irie, H., Y. Watanabe, and K. Hashimoto (2003). Nitrogen- Concentration Dependence on Photocatalytic Activity of TiO2-xNxPowders. The Journal of Physical Chemistry B, 107(23); 5483–5486 Kasuga, T., M.Hiramatsu, A.Hoson, T.Sekino, andK.Niihara (1998). Formation of Titanium Oxide Nanotube. Langmuir, 14(12); 3160–3163 Koh, P. W., M. H. M. Hatta, S. T. Ong, L. Yuliati, and S. L. Lee (2017). Photocatalytic degradation of photosensitizing and non-photosensitizing dyes over chromium doped titania photocatalysts under visible light. Journal of Photochemistry and Photobiology A: Chemistry, 332; 215–223 Lee, K., A. Mazare, and P. Schmuki (2014). One-Dimensional Titanium Dioxide Nanomaterials: Nanotubes. Chemical Re- views, 114(19); 9385–9454 Lee, S. L., J. M. Ekhsan, N. A. Kasiran, and A. A. Aziz (2015). Eect of Titania Loading on Properties and Catalytic Ac- tivity of Nanostructured Phosphate–Vanadia-Impregnated Silica–Titania Oxidative–Acidic Bifunctional Catalyst. Inter- nationalJournal of ChemicalReactorEngineering, 13(1); 21–28 Lee, S. L., S. P. Khaw, and Y. K. Ooi (2016). Vanadium oxides doped porous titania photocatalysts for phenol photodegra- dation. Malaysian Journal of Fundamental and Applied Sciences, 12(1); 28–33 Leong, C. Y., P. W. Koh, Y. S. Lo, and S. L. Lee (2020). Hydrothermal synthesis of titanium dioxide nanotube with methylamine for photodegradation of Congo red. IOP Con- ference Series: Materials Science and Engineering, 833; 012075 Li, X., D. Wang, G. Cheng, Q. Luo, J. An, and Y. Wang (2008). Preparation of polyaniline-modied TiO2 nanoparticles and their photocatalytic activity under visible light illumination. Applied Catalysis B: Environmental, 81(3-4); 267–273 Ooi, Y. K., M. H. M. Hatta, and S. L. Lee (2020). Properties and Photocatalytic Behaviour of Vanadia Loaded Titania Supported on MCM-41 Synthesized using Dierent Sur- factants for Degradation of Methylene Blue. Journal of the Indonesian Chemical Society, 3(1); 28–28 Ooi, Y. K., L. Yuliati, and S. L. Lee (2016). Phenol photo- catalytic degradation over mesoporous TUD-1-supported chromium oxide-doped titania photocatalyst. Chinese Journal of Catalysis, 37(11); 1871–1881 OU, H. and S. LO (2007). Review of titania nanotubes synthe- sized via the hydrothermal treatment: Fabrication, modica- tion, and application. Separation and Purication Technology, 58(1); 179–191 Sathish, M., B. Viswanathan, R. P. Viswanath, and C. S. Gopinath (2005). Synthesis, Characterization, Electronic Structure, and Photocatalytic Activity of Nitrogen-Doped TiO2Nanocatalyst. Chemistry of Materials, 17(25); 6349– 6353 Sun, W.-T., Y. Yu, H.-Y. Pan, X.-F. Gao, Q. Chen, and L.-M. Peng (2008). CdS Quantum Dots Sensitized TiO2Nanotube-Array Photoelectrodes. Journal of the Ameri- can Chemical Society, 130(4); 1124–1125 Weng, L.-Q., S.-H. Song, S. Hodgson, A. Baker, and J. Yu (2006). Synthesis and characterisation of nanotubular ti- tanates and titania. Journal of the European Ceramic Society, 26(8); 1405–1409 Wojcieszak, D., D. Kaczmarek, J. Domaradzki, and M. Mazur (2013). Correlation of Photocatalysis and Photolumi- nescence Eect in Relation to the Surface Properties of TiO2:Tb Thin Films. International Journal of Photoenergy, 2013; 1–9 Xiong, G., Q. Jia, Y. Cao, L. Liu, and Z. Guo (2017). The eect of acid treatment on the active sites and reaction in- termediates of the low-cost TS-1 in propylene epoxidation. RSC Advances, 7(39); 24046–24054 Xu, L., D.-D. Huang, C.-G. Li, X. Ji, S. Jin, Z. Feng, F. Xia, X. Li, F. Fan, C. Li, and P. Wu (2015). Construction of unique six-coordinated titanium species with an organic amine ligand in titanosilicate and their unprecedented high eciency for alkene epoxidation. Chemical Communications, 51(43); 9010–9013 © 2021 The Authors. Page 73 of 73 INTRODUCTION EXPERIMENTAL SECTION Materials Methods RESULTS AND DISCUSSION Structural Properties Morphology of the Samples Optical Properties Photoluminescence Study Photocatalytic Testing CONCLUSIONS ACKNOWLEDGEMENT