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This study investigated the removal of synthetic and natural dyes from wastewater using TiO2-chitosan-coated glass beads. The glass bead system was performed to evaluate the adsorption and photodegradation properties of TiO2-chitosan under both batch and flow conditions under UV-C light irradiation. The removal of synthetic, natural, and wastewater dyes in batch systems under UV-C irradiation was found to be 99%, 98%, and 70%, respectively. For the flow systems, the removal efficiency of synthetic, natural, and wastewater dyes was observed to be 99%, 99%, and 90%, respectively, with adsorption capacity of 0.011 mg/g within 180 min. The pseudo-second-order kinetic model most accurately analyzes the adsorption process. Additionally, TiO2-chitosan-coated glass beads exhibited good reusability over five cycles, maintaining high removal efficiency. The findings indicate that TiO2-chitosan-coated glass beads in a flow system show superior efficiency for the breakdown of organic dyes compared to that in a batch system. This research offers an optimistic approach to treating dye-contaminated water dealing with an environmentally sensitive issue, contributing to advancing sustainable practices in batik production.

The hydroxyapatite/alginate (HAp/Alg) composite was synthesized using an in-situ precipitation route. The effect of pH (8, 9, 10, and 11) and calcination temperature (300, 500, 700, and 900 °C) were studied by characterization techniques such as X-ray diffraction (XRD), Fourier-transform infrared (FTIR), and scanning electron microscopy with energy-dispersive X-ray (SEM with EDAX). XRD results show the hexagonal crystal system of HAp for each pH value and the biphase (HAp and whitelockite) for the sintering temperature at 700 and 900 °C. The FTIR spectra show no impurity peaks. SEM images revealed spherical-like (HAp/Alg-11) and flake-like (HAp/Alg-900) particles with good homogeneity, size, and shape that could be notable for biomedical utilization, such as drug delivery material. Drug loading and release ability of pure HAp, HAp/Alg-11, and HAp/Alg-900 composites have been investigated with clindamycin hydrochloride as the drug model. The maximum clindamycin HCl release from HAp, HAP/Alg-11, and HAp/Alg-900 reached 74.48, 92.75, and 69.65% in the 8th hour. HAp/Alg-11 has the highest release because it has the largest surface area of 162.584 m2/g. Antibacterial test results showed HAp/Alg-11 has antibacterial activity against Staphylococcus aureus and Escherichia coli, confirming that HAp/Alg-11 composite has the potential to be applied as drug delivery.

This study investigates the synthesis of TiO2 using the rind of Aloe vera (L.) Burm extract as a green-capping agent. It was discovered that adding the studied extract up to 10 % (TOAv10) increased the surface area and pore volume while maintaining the spherical shape of the nanoparticles. Overall, the TOAv4 sample has the highest photocatalytic activity compared to other samples and a good photocatalytic activity compared to TiO2 prepared without extract. The current findings provide an environmentally friendly and low-cost protocol for the synthesis of TiO2 nanoparticles in the application of wastewater treatment.

In this study, the generation of 1D TiO2 nanowires was controlled by introducing NH4OH in a one-step hydrothermal method. The increasing amount of NH4OH reduced the width of the resulting TiO2 nanowires, revealing that NH4OH altered the morphologies of the synthesized TiO2 nanowires. NTW20 showed the best photoreduction performance since NTW20 had smaller widths, large surface area and more efficient redox reaction on the surface. In comparison, the absence of photocatalyst yielded a low photoreduction activity of 5.7 %, indicating that the synthesized TiO2 nanowires showed an excellent performance in photocatalysis reactions.

Through a combination of biosynthetic and hydrothermal methods, N-doped TiO2 photocatalyst has been successfully synthesized using various concentrations of ammonia as a nitrogen source, namely 10% w/w (NTO10), 20% w/w (NTO20), 35% w/w (NTO35), and 50% w/w (NTO50). The synthesis of TiO2 was conducted using Aloe vera (L) Burm F. rind extract as a natural capping agent via the biosynthetic method, followed by a nitrogen doping process via the hydrothermal method. The X-ray Diffraction (XRD) analysis revealed that all phases were anatase. According to the results of the UV-Vis Diffuse Reflectance Spectroscopy (UV-Vis DRS) analysis using the Tauc-Plot method, all N-doped TiO2 samples showed a decrease in the energy gap compared to the TO sample. This indicates that the doping of TiO2 using nitrogen has been successfully doped into TiO2. The photocatalytic activity of N-doped TiO2 was evaluated for the photoreduction of the Cr(VI) model pollutant using a 24-watt LED lamp as a visible light source for 120 minutes. The results indicate that the NTO35 is the best-prepared N-doped TiO2, which showed a reduced rate for the Cr (VI) model pollutant of 50.88%, or two times greater than that of undoped TiO2.

The use of feed in fish farming is often inefficient because fish only partially consume the feed spread in ponds, so it becomes waste for the aquatic environment and, even worse, will trigger new diseases. The Department of Chemistry's of Universitas Andalas team was trying to overcome this problem by increasing the efficiency of fish feed. For the feed to work optimally and produce good quality fish weight, it is necessary to modify the nutrition of the fish feed, one of which is by adding probiotics through a fermentation process. The method used in this activity includes training, mentoring, and demonstration plots in feed fermentation and counselling regarding the right time to feed. This activity targets fish farmers in the Koto Luar area, Pauh District, Padang, with a fish culturing group, "Family Sepakat", as the partner. Feed fermentation was carried out with probiotic starters such as Bacillus sp., saccharomyces cerevisiae, L. fermentum, L. plantarum, and W. paramesenteroides. This activity improved catfish growth, and the death rate was lower than in catfish farming without feed fermentation treatment.

The electrical conductivity of low concentrations of lanthanum-doped SrTiO3 nanocube ceramics synthesized using the facile solvothermal method in mixed organic and inorganic solvents with cetyltrimethylammonium bromide (CTAB) as a capping agent and tert-butyl amine (TBA) as a mineralizer was investigated. X-ray diffraction patterns confirmed the formation of a high-purity perovskite phase, corresponding to the standard data and the pattern refinement results. The particles of the sample were nanocubes, whereas the La-doped SrTiO3 sample particles were more uniform in size and shape, as shown in TEM images. The FT-IR spectrum confirmed the vibration of the CH3-N+ groups from CTAB and TBA, indicating an electrostatic interaction between their functional groups and the particle surface. Substitution of La3+ ions at low concentrations increased electrical conductivity compared to the undoped SrTiO3 sample. Lanthanum donates excess electrons, thereby increasing the number of electron carriers, which causes a reduction in the band gap energy according to the UV-DRS spectrum analysis using the Tauc equation.

Porous N-doped TiO2 photocatalyst was successfully synthesized by an environmentally friendly peroxo sol-gel method using polyethylene glycol (PEG) as a templating agent. Here, the effect of PEG addition to the aqueous peroxotitanium solutions on the structure, pore properties and photocatalytic activity of the obtained photocatalysts was systematically studied. The prepared photocatalysts were characterized by X-ray diffraction (XRD), UV-Vis diffuse reflectance spectroscopy (DRS), and Brunauer-Emmett-Teller (BET). It was found that the doping of nitrogen narrows the band gap of TiO2 leading to enhance its visible-light response. The BET analysis shows that the prepared photocatalysts have a typical mesoporous structure with pore sizes of 3–6 nm. The photocatalytic activity of the prepared photocatalysts was evaluated by photocatalytic reduction of Cd(II) in an aqueous solution under visible light irradiation. The results show that porous N-doped TiO2 with the optimal PEG addition had the highest Cd(II) reduction of 85.1% after 2.5 h irradiation in neutral aqueous solution. This significant improvement in photocatalytic activity of the prepared photocatalysts was mainly attributed to the synergistic combination of N doping and porous structure, which could actively increase the catalytic active site of this photocatalysts. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

The polycrystalline SrTiO3 thin films were prepared by the sol-gel-hydrothermal method on glass substrates. The synthesis pathway was initiated by preparing a clear TiO2 solution using the sol-gel method. This clear solution was then deposited on a glass substrate using the dip coating technique, followed by the transformation of a thin layer of TiO2 into SrTiO3 by the hydrothermal method. The crystal structure, bond interactions, and band gap energy of SrTiO3 thin layers were characterized using X-ray Diffraction (XRD), Fourier Transform Infra-Red spectroscopy (FTIR), and UV–Vis Diffuse Reflectance Spectroscopy (UV-DRS). The XRD patterns of all SrTiO3 thin layers indicated the perovskite structure of the samples. The FTIR spectrum showed an interaction of the silanol groups on the surface of the glass substrate with Ti–O–Ti of SrTiO3 layers. The characteristics of the UV-DRS spectrum were influenced by the thickness of the SrTiO3 layer formed on the glass substrate. The findings of this work provide insights for producing SrTiO3 layers with specified thickness and morphology.

The Qur'an Education Park (TPQ) and Tahzhul Qur'an House (RTQ) of the Raudhatul Adzkia Jorong Dalam Koto Nagari Koto Tangah, Tilatang Kamang, and District of Agam have been launched since 2015. The students who study here are free of charge. The operational costs of education and the honorarium for educators come from donations from their community and some nomads. However, this contribution is not sufficient for operational costs. The Department of Chemistry's community service team, Andalas University, collaborated with partners to start a business to solve this problem. The business was carried out using vacant land owned by partners for catfish cultivation. Surveys, program socialization and assisting activities were carried out online using virtual media, while Partners carried out the implementation in the field. Activities carried out were pond preparation, the release of catfish seeds, feeding, sorting, maintenance, harvesting, and marketing cultivated catfish. Based on the evaluation, 5000 seedlings from the released catfish developed well. About 99% of catfish typically growth to a large and even size, while the other 1% growth relatively slowly. Harvested catfish were sold for IDR 18,000/kg for wet fish and IDR 100,000/kg for dried fish. This business has been carried out sustainably by partners, and the profits have been used to support the operational costs of TPQ and RTQ Raudhatul Adzkia.

This study aimed to get an insight into the adsorption of three synthetic dyes onto chitin using experimental and computational approaches. The successful preparation of α-chitin was confirmed using the Fourier Transform Infrared (FTIR) and X-ray Diffraction (XRD). In addition, the presence of porous and fiber on the surface of the extracted chitin was revealed by the Scanning Electron Microscopy (SEM) analysis. The extracted α-chitin was then used as an adsorbent to remove synthetic dyes, namely Malachite green, Basic red 18, and Alizarin yellow R. The kinetic study showed that the adsorption of dyes was well-described using a pseudo-second-order model, whereas the isotherm adsorption obeyed the Freundlich model. The Frontier Molecular Orbital (FMO) revealed several locations of dyes and chitin molecules that are potentially active sites for adsorption. The adsorption trend could be related to the Highest Occupied Molecular Orbital (HOMO) – Lowest Unoccupied Molecular Orbital (LUMO) energy gap and electrophilicity index of the dyes. The Conductor-like Model for Real Solvent (COSMO-RS) model demonstrated, for the first time, that several interactions occurred during the adsorption of dyes onto α-chitin. For the Malachite green and Basic Red 18, the Van der Waals forces of the dyes controlled its adsorption behavior. In contrast, the hydrogen bonding interaction governed the adsorption behavior of Alizarin yellow R dye onto α-chitin. The gathered insight from this work might guide us better to understand the molecular level of dyes–chitin interactions and, ultimately, to design adsorbents to remove synthetic dyes from wastewater.

The tropical bamboo has been widely used in modern society as a potential material for various applications. It is well known that bamboo has low durability due to its hydrophilic properties. To overcome this problem, the superhydrophobic surface on Indonesian bamboo timber had been successfully fabricated via hydrothermal deposition of an anatase TiO2 and solution immersion of octadecyltrichlorosilane (ODTS), which exhibited a maximum water contact angle (WCA) of 155°. The as-fabricated superhydrophobic bamboo timber not only showed high mechanical resistance against the abrasion of SiC sandpaper but had also been proven to possess high chemical stability after immersion in acidic and basic aqueous solutions. Moreover, the superhydrophobic bamboo timber also demonstrated excellent self-cleaning and flame-resistance properties, in comparison to pure bamboo timber. It is believed that the strategy offered in this study can increase the utilization of bamboo timber for various purposes, especially as a self-cleaning material.

Diazinon (C12H21N2O3PS) is an effective pest controller that has been frequently used by farmers in agriculture. It is a nonspecific and highly toxic pesticide having low persistence in the environment and categorized as moderately hazardous class II. The degradation of commercial diazinon in aqueous solution was investigated by photocatalysis using low-energy activated C,N-codoped TiO2 as catalyst under visible-light. The influence of some parameters, i.e., catalyst concentration, the initial concentration of diazinon, initial pH of diazinon, and irradiation time on the diazinon degradation was studied. The amount of diazinon degradation was strongly influenced by all the above parameters. The results show that titania-modified enhanced the degradation percentage of diazinon, from 44.08% without a catalyst to 86.93% by adding 12 mg C,N-codoped TiO2 catalyst after 30 minutes visible-light irradiation. UV-visible spectrophotometer, HPLC, and COD analysis verified that diazinon was successfully degraded under photocatalysis visible.

Fenol merupakan senyawa kimia yang banyak digunakan dalam proses industri. Akan tetapi fenol dalam konsentrasi berlebihan dapat menimbulkan efek buruk terhadap kehidupan manusia dan lingkungan pada umumnya. Pada penelitian ini, fenol didegradasi secara fotolisis tanpa dan dengan menggunakan katalis TiO2/C di bawah sinar UV (10 Watt, λ= 365 nm) dan sinar tampak (lampu philips LED 13 watt 1400 lux, λ= 465-640 nm). Larutan fenol yang telah didegradasi diukur dengan Spektrofotometer UV-Vis pada panjang gelombang 200-400 nm. Hasil karakterisasi XRD dan DRS UV-Vis memperlihatkan bahwa katalis modifikasi titania menggunakan unsur karbon berpotensi aktif pada sinar tampak. Aplikasi katalis TiO2/C mampu meningkatkan efisiensi dari degradasi fenol pada sistem fotolisis. Larutan fenol 8 mg/L terdegradasi sebanyak 38,98% dan 35,59% tanpa katalis dan meningkat menjadi 51,69% dan 66,10% dengan penambahan 5 mg katalis TiO2/C masing-masing di bawah sinar UV dan sinar tampak.ABSTRACTPhenol is a chemical compound that is widely used in industrial processes. However, phenol in excessive concentration can endanger human life and the environment. In this study, phenol was degraded without and using TiO2/C catalyst under UV-light (10 Watts, λ = 365 nm) and visible-light (13 watt Philips, lux= 1400, λ = 465-640 nm) photolysis. The degraded of phenol solution was measured by a UV-Vis spectrophotometer at a wavelength 200-400 nm. The results of XRD and DRS UV-Vis characterization show that the modified of titania catalyst using carbon potentially actives in visible-light. Application of TiO2/C catalyst can improve the efficiency of phenol degradation in photolysis system. Phenol solution with concentration 8 mg/L was degraded by 38.98% and 35.59% without catalyst and increased to be 51.69% and 66.10% in presence of 5 mg TiO2/C catalyst under UV-light and visible-light, respectively.

Zat warna orange-F3R dan violet-3B merupakan zat warna organik sintetis turunan vat yang bersifat non-biodegradable. Degradasi kedua zat warna ini telah dilakukan secara sonolisis dengan penambahan katalis semikonduktor TiO2 anatase yang didoping karbon dan nitrogen. Proses sonolisis menggunakan iradiasi ultrasonik dengan frekuensi 35 kHz. Massa katalis optimum yang diperoleh untuk sonolisis zat warna orange-F3R adalah 9 mg dan 6 mg untuk violet-3B. Persen degradasi meningkat secara signifikan dengan penambahan katalis yaitu dari 8.3% menjadi 36.2% untuk sonolisis zat warna orange-F3R selama iradiasi 180 menit. Sedangkan, dengan waktu iradiasi yang sama persen degradasi dari zat warna violet meningkat dari 5.8% menjadi 34.2% setelah penambahan katalis. Kata kunci: C-N-codoped TiO2, sonolisis, ultrasonik, vat Orange-F3R and violet-3B are non-biodegradable synthetic organic dyes. The degradation of these two dyestuffs has been done by sonolysis process with the addition of semiconductor TiO2 anatase catalyst which is doped by carbon and nitrogen atoms. The sonolysis process used ultrasonic irradiation with a frequency of 35 kHz. The optimum catalyst mass obtained for the orange-F3R dye sonolysis was 9 mg and 6 mg for violet-3B. The percentage of degradation increased significantly with the addition of the catalyst; it was from 8.3% to 36.2% for the orange-F3R dye during irradiation for 180 min. Meanwhile, by the same irradiation time, the degradation percentage of violet dye increased from 5.8% to 34.2% after the addition of the catalyst. Keywords: C-N-codoped TiO2, sonolysis, ultrasonic, vat-dye.

SrTiO3 bulat berongga yang tersusun dari nano kubus telah disintesis dengan penambahan cetyltrimethylammonium bromide (CTAB) sebagai capping agent untuk mengontrol morfologi partikel. Kondisi sintesis pada suhu 220 °C selama 48 jam dengan perbandingan mol Sr:Ti = 1:1.25 dan perbandingan material awal dengan CTAB adalah 1:0.5 menghasilkan partikel dengan kristalinitas yang tinggi pada puncak spesifik 2θ = 32.41o bidang 110 yang merujuk pada struktur perovskit kubus. Penghalusan struktur kristal dengan metoda Rietveld menunjukkan bahwa struktur kristal hasil pengukuran memiliki kecocokan yang tinggi dengan hasil perhitungan dengan nilai Rwp adalah 12.07. Interaksi antara CTAB dan permukaan SrTiO3 terlacak pada spektrum FTIR dengan angka gelombang 1100-1250 cm-1 membuktikan adanya vibrasi ulur C-N yang melemah akibat proses capping. Foto SEM menunjukkan bahwa partikel yang terbentuk umumnya memiliki bentuk bulat berongga, sementara foto TEM memperlihatkan partikel berongga berukuran mikro dibentuk dari susunan nanokubus berukuran rata-rata 20 nm. Kata kunci: Capping agent, partikel berongga, nanokubus, solvotermal, perovskite The synthesis of SrTiO3 hollow sphere built as assembly of nanocubes using cetyltrimethylammonium bromide (CTAB) as capping agent was aimed to control the size and shape of the particles. The condition of the synthesis at 220 °C for 48 hours with a molar ratio of Sr:Ti was 1:1.25 and starting material:CTAB was 1:0.5, have resulted the particles with a high crystallinity with specific XRD peaks at 2θ; 32.41 (110), which was in agreement with the cube-perovskite structure. The refinement of the crystal structure by the Rietveld method showed that the crystal structure of the measurement results has a high match with the result of the calculation with Rwp value was 12.07. The interaction between CTAB and the surface of SrTiO3 traced in the FTIR spectrum with wave number 1100-1250 cm-1 indicated the stretching vibration of C-N was weakened due to the capping process. SEM images showed the particles with hollow microsphere, while TEM images revealed that the hollow particles were assembled by nanocubes with an average size of 20 nm. Keywords: Capping agent, hollow, nanocube, solvothermal, perovskite.

The ultra-hydrophobic surface on Indonesia bamboo timber has been successfully prepared using OFP (2,2,3,3,4,4,5,5-octafluoro-1-pentanol) as a modifier agent. The hydrothermal method has been used to fabricate anatase TiO2 film followed by OFP modification. Maximal water contact angle of 123ο has been obtained for the composition of 10 mL of OFP and 15 mL of 2-propanol (B-T-OFP10). XRD analysis showed the existence of pure anatase TiO2 film on bamboo timber, confirmed by EDS result. SEM image of a TiO2-coated and a typical ultra-hydrophobic bamboo timber revealed irregular aggregates of spherical TiO2 on the surface and compact ultra-hydrophobic surface, respectively. The optimum sample (B-T-OFP10) showed excellent mechanical stability, self-cleaning property, and flame retardancy compared to pure bamboo timber.

C-N-codoped TiO2 (CNTO) photocatalysts were successfully synthesized by using “green” method peroxo sol-gel. XRD results revealed the presence of anatase phase only for all samples. The result of Scanning Electron Microscope-Electron Dispersive X-Ray (SEM-EDX) showed surface morphology of CNTO10 was spherical (44 nm) and homogeneous. Diffuse Reflectance Spectra UV-Vis (DRS UV-Vis) result showed red shift in absorbance indicating successful modification of TiO2 by C and N. The result of photocatalytic activity in reducing Cr(VI) showed that the Cr(VI) reduction increase with the increase of irradiation time and photocatalyst’s mass. The highest Cr(VI) reduction was 90.07% for CNTO10 sample. This is due to the synergistic effects of C and N dopants that improves TiO2 photocatalytic activity under visible light irradiation.

Paracetamol is generally used as analgesic and antipyretic drugs. Contamination paracetamol in the environment can occur because of waste material disposal from production site and immediate disposal of household that cause water pollution. Paracetamol is degraded by photolysis method under irradiation 10 watt UV-light (λ=365 nm), visible-light (Philips LED 13 watt 1400 lux) and solar-light with and without addition C-N-codoped TiO2catalyst. The solution is analyzed by UV-Vis spectrophotometer at λ 200-400 nm. Optimum weight of C-N-codoped TiO2 catalyst obtained is 20 mg under UV-light photolysis. Paracetamol 4 mg/L is degraded 45.48% after 120 minutes under UV-light irradiation without catalyst, and increases to be 69.31% by using 20 mg catalyst. While degradation percentage of paracetamol is 16.96 % without catalyst, the percentage increases to be 34.29% after using 20 mg catalyst for 120 minutes photolysis under visible-light. Degradation of paracetamol by solar light achieves only 12.27% in absance of catalyst for 120 minutes irradiation, but it increases significantly until 70.39% in presence of 20 mg catalyst.

The synthesis of SrTiO3 nanocubes have been carried out by solvothermal process using cetyl trimethyl ammonium bromide (CTAB) as capping agent to control the particles morphology. The condition of the synthesis was obtained at 160 ºC for 24 hours with molar ratio of SrTiO3 and capping agent was 1 : 1. The X-ray diffraction (XRD) pattern shows that SrTiO3 adopts a perovskite structure with a higher intensity of 110 at 2q:32.33º and the crystallite size calculated from FWHM was found to be 41 nm. Fourier transform infrared (FTIR) spectrum shows a shift in particular absorption band attributed the interaction between SrTiO3 particles surface and the head group of CTAB molecules. Transmission electron microscopy (TEM) image shows the cubic-like particles of SrTiO3, this indicatesthat CTAB successfully functions as capping agent on the synthesis of SrTiO3.

Direct red-23 and Direct violet are non-biodegradable compounds containing azo component and carcinogenic. Direct red-23 and Direct violet had been degraded by ozonolysis, photolysis with UV lamp and solar irradiation methods using N-doped TiO2 catalyst. UV/Vis Spectrophotometer at wavelength 300-800 nm was used to measure the absorption of sample solution. The optimum weight of N-doped TiO2 catalyst was 20 mg. From the three methods obtained that ozonolysis method was the faster degradation process than photolysis with UV and solar irradiation. Direct red-23 and Direct violet was degraded as much as 55 and 50% within 20 minutes by ozonolysis.ABSTRAKZat warna Direct red-23 dan Direct violet merupakan senyawa non-biodegradable yang mengandung senyawa azo dan bersifat karsinogen. Direct red-23 dan Direct violet didegradasi menggunakan metode ozonolisis, fotolisis dengan sinar UV dan dengan penyinaran matahari, tanpa dan dengan katalis N-doped TiO2. Hasil penelitian diukur dengan spektrofotometer UV-Vis pada panjang gelombang 300-800 nm. Berat optimum katalis N-doped TiO2 didapatkan 20 mg. Dari ketiga metode didapatkan bahwa proses degradasi pada metode ozonolisis paling cepat dibandingkan dengan fotolisis sinar UV dan cahaya matahari. Direct red-23 dan Direct violet dapat didegradasi sebanyak 55 dan 50% dalam waktu 20 menit.

Zat warna direct red-23 merupakan pewarna sintetik dengan struktur senyawa organik yang bersifat non-biodegradable. Zat warna direct red-23 mengandung senyawa azo dan bersifat karsinogenik. Zat warna direct red-23 didegradasi secara fotolisis menggunakan sinar UV (ultraviolet), sinar matahari, tanpa dan dengan penambahan katalis C-N-codoped TiO2. Larutan zat warna direct red-23setelah dan sebelum didegradasi diukur dengan spektrofotometer UV-Vis pada panjang gelombang 400-800 nm. Penentuan berat optimum katalis C-N-codoped TiO2 dilakukan dengan metode fotolisis sinar UV dan didapatkan berat optimum 15 mg. Persen degradasi zat warna direct red-23 secara fotolisis sinar UV dan sinar matahari tanpa katalis C-N-codoped TiO2 27.47% dan 13.74%. Persen degradasi meningkat menjadi 68.68% dan 28.57% dengan penambahan 15 mg katalis C-N-codoped selama 120 menit fotolisis. Dari penelitian dapat disimpulkan metode fotolisis dengan sinar UV lebih efisien dibandingkan dengan sinar matahari. Direct red-23 dye is a synthetic dye that is widely used in textile industry. Wastes generated from textile industrial processes are generally non-biodegradable organic compounds containing azo compounds and carcinogenic. Direct red-23 dye was degraded by photolysis UV Light method, solar irradiation, without and addition of C-N-codoped TiO2 catalyst. The results degradation of direct red-23 were measured with a UV-Vis spectrophotometer at wavelength of 400-800 nm. Determination of optimum weight of the C-N-codoped TiO2 catalyst was performedby photolysisUV Light methodand the optimum C-N-codoped TiO2catalyst is obtained 15 mg. Percent degradation of direct red-23 dye by photolysis of UV light and solar irradiation without C-N-codoped TiO2to 27.47% and 13.74%. Percent degradation increasedto 68.68% and 28.57% by addingC-N-codoped TiO2 catalyst was adding 120 menutes of photolysis.From the research it can be concluded by photolysis with UV Light methodis more efficient compared to solar radiation.

The photocatalytic properties of TiO2 compound in anatase phase can be activated under visible light by nitrogen modification and its ability can be increased by generated porous structure using polietilen glikol (PEG) on TiO2 thin film surface. The porous N/TiO2 thin films were prepared by heating aqueous peroxotitanate thin films by addition of polietilen glikol (PEG) deposited uniformly on superhydrophilic uncoated glass at 500 oC for 1 h. The result of X-ray diffraction (XRD) confirmed the resence of only anatase phase for all samples. The UV-Vis spectroscopy showed the synthesized porous N/TiO2 thin films exhibit the absorption in the visible range (400-500 nm). Photocatalytic activity of porous N/ TiO2 thin films were evaluated by using fourier transform-infrared spectroscopy (FTIR) to determine the ability of this photocatalyst for stearic acid degradation under visible light irradiation. The result showed that N/TiO2/PEG-2.1 thin film degraded the stearic acid was about 87,86%, which was 1,12 times higher than that of N-doped TiO2 and 9,9 times higher than that of undoped TiO2 thin film.