Fabrication of IrO2 decorated vertical aligned self-doped TiO2 nanotube arrays for oxygen evolution in water electrolysis

To fabricate effective and stable OER electrode in water electrolysis, self-doped TiO₂ nanotube arrays which has a higher electrical conductivity than pristine TiO₂ nanotube arrays was used as the support for loading IrO₂. The self-doped TNTA was fabricated by a simple electrochemical reduction of TNTA in neutral electrolyte solution, and then IrO₂ nano particles were deposited by pulse electro-deposition method. The cyclic voltammetric behavior, electrical conductivity and micro structure of self-doped TNTA prepared at different reduction potential were characterized to obtain an optimal performance, and self-doped TNTA prepared under ?1.9 V (vs. Ag/AgCl) shows the best electrochemical performance. After depositing IrO₂, the OER activity and stability of new electrodes were also determined. Due to the enhanced electrical conductivity of support, the mass activity of IrO₂/self-doped TNTA are 50 times higher than IrO₂/TNTA. The OER stability of new electrode was evaluated under constant current of 5 mA/cm², IrO₂/TNTA and IrO₂/Ti were also tested for comparison. A higher stability of IrO₂/self-doped TNTA electrode is observed than the other two electrodes, and XPS studies indicate a lower oxidation state of Ir in IrO₂/self-doped TNTA, this shows a possible interactions between IrO₂ and the new support.     

Photocatalytic hydrogen production from glycerol–water mixture over Pt‐N‐TiO2 nanotube photocatalyst

The effects of several modifications on TiO₂ P25 in producing hydrogen from glycerol–water mixture have been investigated. Prior to further modification, TiO₂ underwent hydrothermal treatment at 130°C for several hours to obtain nanotube shape. TiO₂ nanotubes (TiNT) was then doped with platinum (Pt) and nitrogen (N) by employing photo‐deposition and impregnation method, respectively. SEM and XRD results showed that Pt‐N‐TiNT was successfully obtained as pure anatase crystal structure. The effects of glycerol content to photocatalytic activity of hydrogen production have also been studied, result in 50%v of glycerol as the optimum concentration correspond to the stoichiometric volume ratio of glycerol reforming. The results of photo‐production test showed that TiNT (nanotube) could enhance hydrogen generation by two times compared with unmodified P25 (nanoparticle). Meanwhile, simultaneous modification of TiNT by Pt and N dopants (Pt‐N‐TiNT) lead to activity improvement up to 13 times compared with P25. The output of this study may contribute toward finding an alternative pathway to produce H₂ from renewable resources. Copyright © 2012 John Wiley & Sons, Ltd.     

Kinetic study of oxygen reduction reaction and PEM fuel cell performance of Pt/TiO2-C electrocatalyst

The electrochemical activity and thermal stability of the Pt/TiO₂-C were evaluated in the oxygen reduction reaction (ORR) in acid medium at different temperatures. The platinum was selectively deposited onto the TiO₂ (E_bg = 2.3 eV) by the photo-irradiation of platinum precursor (Pt⁴⁺→Pt⁰). The Pt/TiO₂-C electrocatalyst prepared was characterized by XRD, TEM/EDS, cyclic and lineal voltammetry techniques. TEM images indicated that platinum nanoparticles (<5 nm) were deposited in agglomerates form around the oxide sites. EDS and XRD results confirm the composition and crystalline structure of Pt/TiO₂-C. The thermal stability and electrochemical activity of the Pt/TiO₂-C for ORR at different temperatures (298–343 K) is higher than Pt/C commercial sample (Pt-Etek). A more favorable apparent enthalpy of activation for Pt/TiO₂-C was greatly influenced by addition of oxide in the catalyst compare to Pt-Etek. Single H₂/O₂ fuel cell performance results of Pt/TiO₂-C show an improvement of the power density with the increase of the temperature.     

Comparative study of the effect of TiO2 support composition and Pt loading on the performance of Pt/TiO2 photocatalysts for catalytic photoreforming of cellulose

Herein, catalytic aqueous phase photoreforming of cellulose was carried out over Pt/m-TiO₂ (i.e., mixed phase of anatase and rutile) and Pt/anatase catalysts to investigate the effect of the TiO₂ support structure and Pt loading on the production of H₂. The effect of the TiO₂ support on the properties of the resulting Pt/TiO₂ catalysts (such as actual Pt loading and BET surface area) was not significant. At low Pt loading of 0.16 wt.%, the TiO₂ supports affected the sub-nanometre Pt structures which was confirmed by the diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) characterisation (using CO as the probe). Conversely, the effect of TiO₂ supports on larger Pt particles (on 1 wt.% catalysts) was insignificant possibly due to the reduced effect of restructuration of bigger Pt particles on the TiO₂ supports. With an increase in Pt loading from 0.16 wt% to 1.00 wt.%, the normalised H₂ production rate (with respect to the actual supported Pt amount and specific surface area of the catalysts) showed a decreasing trend over the two types of the catalysts, i.e., from 10.6 to 1.4 μmol h⁻¹ m⁻² mg_Pt⁻¹ for Pt/m-TiO₂, and from 8.5 to 1.2 μmol h⁻¹ m⁻² mg_Pt⁻¹ for Pt/anatase. Specifically, large Pt particle sizes reduced the CO₂/H₂ production from cellulose photoreforming over both Pt/m-TiO₂ and Pt/anatase catalysts, indicting an important role played by Pt particle size in photoreforming. Interestingly, in this study, the m-TiO₂ supported catalysts only showed the benefits of enhanced charge separation across the phase junction in producing H₂ with small Pt particles (at sub-nanometre), whilst, when large Pt particles (at around 1–2 nm) were supported, such a benefit was not significant in cellulose photoreforming. The promoting effect of small, sub-nm particles is attributed to the better capture of photoelectrons from bulk TiO₂ and better activity of H⁺ coupling on small Pt particle. Further fundamental study on such guest-host interactions is devised to optimise Pt/TiO₂ catalysts for improving H₂ production from photoreforming reactions.     

TiO2 nanotubes promoting Pt/C catalysts for ethanol electro-oxidation in acidic media

In this paper, TiO₂ nanotubes/Pt/C (TNT/Pt/C) catalysts for ethanol electro-oxidation were prepared by co-mixing method in solution. TEM and XRD showed that uniform anatase TiO₂ nanotubes were about 100 nm in length and 8 nm in diameter and the TGA results indicated that the amount of H₂O contained in TiO₂ nanotubes was much more than that in anatase TiO₂. The composite catalysts activities were measured by cyclic voltammetry (CV), chronoamperometry and CO stripping voltammetry at 25 °C in acidic solutions. The results demonstrated that the TNT can greatly enhance the catalytic activity of Pt for ethanol oxidation and increase the utilization rate of platinum. The CO stripping test showed that the TNT can shift the CO oxidation potential to lower direction than TiO₂ does, which is helpful for ethanol oxidation.     

Pt nanoparticles deposited on TiO2 based nanofibers: Electrochemical stability and oxygen reduction activity

The electrochemical stability of Pt deposited on TiO₂ based nanofibers was compared with commercially available carbon supported Pt. Prior to the Pt deposition the TiO₂ material, which was either undoped or Nb doped, was air calcined. In one case the undoped TiO₂ was also reduced in a hydrogen atmosphere. XRD analysis revealed that the unreduced TiO₂ was present in the anatase phase, irrespective of whether the Nb dopant was present, whereas the rutile phase was formed due to reduction with H₂. The diameter of the TiO₂ fibers varied from 50 to 100 nm, and the average Pt particle diameter was approximately 5 nm. Pt supported on TiO₂ was more stable than Pt supported on C when subjected to 1000 voltammetric cycles in the range of 0.05-1.3 V vs. RHE. Nb doped TiO₂ showed the highest stability, retaining 60% of the electrochemically active surface area after 1000 cycles compared to the state after 100 cycles, whereas the carbon supported catalyst retained 20% of the active surface area. The commercial catalyst had the highest oxygen reduction activity due to its larger specific area (17.1 m² g⁻¹ vs. 5.0 m² g⁻¹ for Pt/TiO₂-Nb, measured after 100 cycles) and the higher support conductivity. The Pt supported on Nb doped or on H₂ reduced TiO₂ was more active than Pt supported on air calcined and otherwise unmodified TiO₂.     

Nanostructured Bi2O3@TiO2 photocatalyst for enhanced hydrogen production

Here we report on Bi₂O₃ clusters immobilized on anatase TiO₂ nanostructures for an enhanced rate of photocatalytic H₂ evolution. Structural, morphological, and optical properties of the Bi₂O₃@TiO₂ nanocomposite (BT) were characterized by a series of techniques including X-ray diffraction, high resolution transmission electron microscopy, X-ray photoelectron spectroscopy, diffuse reflectance spectroscopy and electrochemical impedance spectroscopy. The catalytic H₂ evolution experiments were carried out under different light sources: natural solar light, LED UV (365 ± 5 nm) and LED visible (420 ± 5 nm) light source. Under the solar light a pristine anatase TiO₂ nanostructured (TNS) catalyst generated 4.20 mmol h^?1 g^?1, whereas in the presence of Bi₂O₃@TNS showed much higher H₂ production 26.02 mmol h^?1 g^?1. The photocatalytic activity of the BT and its reproducible performance for five recycles is ascribed to an efficient separation of photogenerated charge carriers. A plausible reaction mechanism for the H₂ generation is proposed.     

In-situ photo-deposition CuO1−x cluster on TiO2 for enhanced photocatalytic H2-production activity

CuO_1?x cluster-modified TiO₂ (CuO_1?x/TiO₂) photocatalysts were prepared by an in-situ photoreduction deposition of Cu on TiO₂ powder support using copper acetate as a Cu source. The prepared samples without any Pt co-catalyst present an especially high photocatalytic H₂-evolution activity under solar light irradiation with 5% glycerol as sacrificial agent. The optimal CuO_1?x/TiO₂ catalyst with only 1 wt% CuO_1?x exhibits a high activity of 1725 μmol h^?1 g^?1 for H₂ evolution, which reaches 120 times that of TiO₂. The high photocatalytic activity of H₂ production is attributed to the highly dispersed CuO_1?x nano clusters on the surface of the TiO₂. In addition, Pt/CuO_1?x/TiO₂ was also prepared by loading Pt on CuO_1?x/TiO₂ sample, and its photocatalytic hydrogen evolution activity is enhanced 1.8 times compared with that of Pt/TiO₂ for overall water splitting reaction under solar light, demonstrating that a small amount CuO_1?x wondrously improves the photocatalytic activity of Pt/TiO₂ for overall water splitting reaction. This paper reports an economic and simple approach to prepare a photocatalyst with high hydrogen-production activity.     

Recyclable CeO2–ZrO2 and CeO2–TiO2 mixed oxides based Pt catalyst for aqueous-phase reforming of the low-boiling fraction of bio-oil

In this study, a series of CeO₂–ZrO₂ and CeO₂–TiO₂ materials with different composition were prepared, characterized by BET and XRD analysis, and their hydrothermal stability was studied by subjecting the samples to acetic acid solutions at 533 K. All of the materials, especially C1Z1 (50 mol% CeO₂ with 50 mol% ZrO₂) and C1T1 (50 mol% CeO₂ with 50 mol% TiO₂), exhibited excellent stability with no phase transformation and minimal decrease in their specific surface area (SSA) was observed even after 16 h. After being loaded by Pt, these catalysts were used for the aqueous phase reforming (APR) of the low-boiling fraction of bio-oil (LBF) to investigate their catalytic performance. Among these catalysts Pt/C1Z1 and Pt/C1T1 showed superior catalytic activity, probably due to their lowest reduction temperature and the largest amount of O vacancies generated by the reduction of the surface oxygen of well-dispersed CeO₂. Thus, Pt/C1Z1 and Pt/C1T1 were chosen to investigate their recyclability. The catalytic activity and H₂ selectivity of Pt/C1Z1 and Pt/C1T1 can be almost recovered after being calcined in air at 773 K for regeneration. After three cycles, the particle size of Pt/C1Z1 and Pt/C1T1 only experienced a slight increase, while for Pt/Al₂O₃ it increased from 2.9 nm to 7.8 nm. So, compared with Pt/Al₂O₃, the Pt/C1Z1 and Pt/C1T1 catalysts were identified as effective and recyclable candidates for the production of H₂ rich fuel gas from APR of LBF.     

Study on surface states of Pt/TiO2 thin film in different atmospheres

In this paper, the surface states of Pt/TiO₂ thin film were tested in air, H₂ and N₂ flows. Pt/TiO₂ was prepared by means of photoreduction of on anatase nano-TiO₂ powders and was coated on the microscopy glass using powder–sol technique. Powder conductivity method was applied in the analysis of surface states. The experimental results show that a new surface state was formed in air flow; which was 0.43 eV lower than the conduction band edge of TiO₂. In N₂ flow, three surface states, with the energy levels of 0.42, 0.62 and 0.90 eV, respectively, were detected. Compared with that tested in airflow, 0.42 and 0.62 eV could be attributed to Pt and floating bond of TiO₂ respectively, while 0.90 eV might have resulted from the Ti³⁺ formed at high temperature in N₂ flow. The conductivity of the sample tested in H₂ flow increased significantly and was almost unchanged with temperature, which could be interpreted by the dissociative adsorption of H₂ on Pt.     

Deposition of heterojunction of ZnO on hydrogenated TiO2 nanotube arrays by atomic layer deposition for enhanced photoelectrochemical water splitting

The heterojunction of ZnO was deposited on hydrogenated TiO₂ nanotube arrays (H–TiO₂) by atomic layer deposition (ALD) with various cycles. The ZnO was uniformly wrapped with the H–TiO₂ samples and the thickness could be accurately controlled by the cycle numbers of ALD. The higher growth rate ~2.7 Å/cycle was obtained due to the surface amorphous layer, compared with the air-treated samples (A-TiO₂), ~2.3 Å/cycle. When the cycle numbers increased to 200, nanowire arrays appeared. Interestingly, the absorption in the visible light region improved more significantly when ALD ZnO was employed for the H–TiO₂ rather than the A-TiO₂ samples. The H–TiO₂ samples with 42 nm of ALD ZnO exhibited enhanced photoelectrochemical water splitting performances, compared with the A-TiO₂ with 42 nm of ALD ZnO. This was related to the higher degree of the electronic band bending and improved photo-response in the UV and visible light region, resulting from the oxygen vacancies.     

Fabrication of anatase TiO2 tapered tetragonal nanorods with designed {100}, {001} and {101} facets for enhanced photocatalytic H2 evolution

In this study, anatase TiO₂ nanorods with exposed high-energy {100} and {001} facets and low-energy {101} facets were fabricated in the presence of surfactants cetyltrimethylammonium bromide, didecyldimethylammonium bromide, and ammonia via a facile hydrothermal method without the erosive reagent hydrofluoric acid. The particle size and morphology were mainly tuned by regulating the hydrothermal temperature. When the temperature was increased from 150 °C to 180 °C and 200 °C, the length of the nanorods decreased from 700-1000 nm to 400–500 nm and 100–200 nm, respectively. Concurrently, the edges and tops of the truncated tetragonal pyramid of the TiO₂ nanorods became blurry and flattened. The synthesized typical TiO₂ nanorods were then used as photocatalysts, and their performance during the direct generation of H₂ from water was evaluated. The TiO₂ nanorods obtained at 150 °C successfully produced high amounts of H₂ evolution (281.36 μmol) in the presence of methanol as a sacrificial agent under ultraviolet light irradiation for 4 h. The outstanding photocatalytic activity of the nanorods was mainly ascribed to the formation of surface heterojunctions in the edges and corners between adjacent high-energy {001} or {100} facets and low-energy {101} facets. The formed heterojunctions could facilitate charge separation through preferential carrier flow toward the specific facets.     

Preparation and properties of MnO2–TiO2 nanotube array composite electrodes using titanium foam as the current collector

MnO₂–TiO₂ nanotube array composite electrodes were prepared through depositing MnO₂ onto TiO₂ nanotube arrays obtained by anodization of the titanium foam and the effect of morphologies of TiO₂ nanotube arrays on the performance of the electrode was investigated. Results show that the wall thickness, the tube diameter and the tightness among the nanotubes affected the performance of composite electrodes. The areal, quality and volume capacitance value of the optimized sample reached up to 436.2 mF/cm², 1470.8 mF/g and 5452.5 mF/cm³, respectively, at a current density of 0.1 mA/cm², which were significantly higher than those of the MnO₂–TiO₂ nanotube array composite electrodes using planar titanium foil as the current collector. The capacitance retention was 85.7% after 3000 cycles. In addition, the influences of the cations (Li⁺, Na⁺, K⁺, NH₄⁺) and anions (Cl^?, Br^?, I^?, CH3COO^?) in the testing electrolytes on the capacitance properties were also studied in detail.     

Enhanced H2 evolution of TiO2 with efficient multiple electrons transfer modified by tiny CuOx–NiO bimetallic oxides

CuO_x–NiO bimetallic oxides modified TiO₂ catalysts were prepared via a precipitation-photoreduction approach for photocatalytic H₂ production. 0.9%Cu0.1%Ni/TiO₂ exhibited the highest H₂ evolution rate (about 55.4 μmol/g/min) under UV–visible light irradiation (350–780 nm), which is higher than the sum of CuO_x/TiO₂ and NiO/TiO₂ catalyst. Cu species exhibited more reducing valence state including Cu⁰ when deposited on NiO/TiO₂ compared with deposited on TiO₂. The polyvalent Cu species lead to enhanced photocurrent and reduced transfer resistance confirmed by photoelectron chemical analysis. CuO_x–NiO modification of the TiO₂ surface is beneficial for the photoexcited electron transfer, which suppresses electrons recombination. The lifetime of photoexcited electrons was enhanced greatly from 1.16 (TiO₂) to 5.15 ns (CuO_x–NiO/TiO₂). A multiple electrons transfer mechanism for polyvalent bimetallic oxides co-modified TiO₂ was proposed based on careful analysis. This work demonstrated a polyvalent bimetallic oxides modified TiO₂ system with efficient photocatalytic H₂ production which can provide some insightful understanding for bimetallic metal oxides co-catalyst design and H₂ evolution mechanism.     

Effect of NaBF4 addition on the anodic synthesis of TiO2 nanotube arrays photocatalyst for production of hydrogen from glycerol–water solution

Addition of NaBF₄ during anodic synthesis of TiO₂ nanotube arrays (TNTAs) photocatalyst and its application for generating hydrogen from glycerol–water solution has been investigated. The TNTAs were synthesized by anodic oxidation of titanium metal in glycerol electrolyte solution containing NH₄F. During the process, the NaBF₄ with different concentrations were added to the solution. Annealing of the formatted TNTAs were performed at 500 °C for 3 h under 20% H₂ in argon atmosphere, to produce crystalline phase photocatalyst. FESEM analysis showed that self-organized and well ordered TNTAs have range of inner diameters, wall thicknesses and lengths approximately 62–130 nm, 27 nm and 1.53 μm, respectively. FTIR analysis indicated that carbon, nitrogen and boron were incorporated into the TNTAs lattice. Refer to UV–Vis DRS and XRD analysis, the TNTAs photocatalysts prepared have the band gap range of 2.70–3.10 eV, with mostly have anatase phase. The NaBF₄ addition during synthesis, resulted modified TNTAs that can reduce the recombination of photo-induced electrons-holes. Photocatalytic hydrogen production test, from glycerol–water solution, indicated that TNTAs with the addition of NaBF₄ during anodic synthesis process showed higher hydrogen production comparing to the one without NaBF₄ addition. Among them the TNTAs,b (with the addition 5 mM of NaBF₄) showed up to 32% improvement in the hydrogen production and can be considered as the optimum condition.     

Enhancing methanol oxidation with a TiO2-modified semiconductor as a photo-catalyst

The direct methanol fuel cell (DMFC) is currently one of the most promising alternative power sources because of its high energy, simple design and operation. However, the DMFC still faces several problems, such as sluggish methanol oxidation and oxygen reduction, as well as a high methanol crossover. In other areas of study, it is well-known that methanol can be photocatalytically oxidized by wide band gap semiconductors under solar illumination. Methanol has been used in photocatalytic water splitting to enhance the performance of photo-electrochemical cells (PECs). Therefore, by combining photocatalytic and electro-catalytic mechanisms, methanol is expected to promote a new type of photo-assisted DMFC. In this work, the semiconductor TiO₂ was used as a photo-catalyst in a PEC using a methanol solution. A TiO₂ P25 suspension was cast onto carbon paper and then dried at 80 °C for 60 min. The photo-electrochemical measurements were carried out in a 3-arm electrochemical cell, using Pt wire as the counter electrode and Ag/AgCl as the reference electrode. Linear scan voltammetry (LSV) was carried out using a 20 V/400 mA potentiostat. The current densities of the electrode were monitored with and without simulated solar illumination. From the investigation, the current density of the TiO₂ electrode under solar illumination was higher than it was without solar illumination. However, the value is low due to the low activity of TiO₂ under visible light illumination. Further studies were carried out by combining TiO₂ with a carbon material and a noble metal alloy to maximize the current density. This modified photo-catalyst can be utilized in a new photo-assisted DMFC to produce higher electricity.     

Probing plasmonic Ag nanoparticles on TiO2 nanotube arrays electrode for efficient solar water splitting

Decoration of semiconductors with plasmonic nanoparticles provides a new direction for efficient solar water splitting for hydrogen production. Herein, Ag nanoparticles as the plasmonic metal were electrodeposited on a TiO₂ nanotube arrays (TNTA) photoelectrode by controlling deposition-charge density. The resulting Ag/TNTA electrode with 10–50 nm diameter Ag nanoparticles exhibited a higher photocurrent density and hydrogen production rate than a bare TNTA electrode under AM 1.5 irradiation. The origins of this enhancement were explored by analyzing the photoelectrochemical behaviors with the relevant optical properties. The absorption of these Ag/TNTA electrodes in the visible light region increased owing to the surface plasmon resonance (SPR) effect of the Ag nanoparticles, and only low photocurrent densities under visible light irradiation were observed. The overall enhancement is owing to the greater incident photon-to-electron conversion efficiency in the 300–400 nm range that is more dependent on the interfacial charge transfer from TNTA to Ag nanoparticles. The localized electronic field of the SPR also reduces the electron transport time in the Ag/TNTA electrodes.     

Influence of Pt deposition on water-splitting hydrogen generation by highly-ordered TiO2 nanotube arrays

Highly-ordered TiO₂ nanotube arrays (TNTAs) were fabricated on Ti sheets by electrochemical anodization. Uniform Pt nanoparticles with an average diameter of 3 nm could be successfully located on the TiO₂ nanotubes on only one side (Pt/TNTAs) or both sides of the Ti sheet (Pt/TNTAs/Pt). Pt/TNTAs, the single-sided Pt deposited TNTAs, could be directly used to split water without a counter electrode. The hydrogen evolution rate can reach 120 μmol h⁻¹ cm⁻² in a mixed solution of 0.5 M Na₂SO₄ and 0.5 M ethylene glycol without any applied bias, which is six times of that by the pure TNTAs. In comparison to the traditional three electrode system, this single-sided Pt deposited TNTAs is a much more simple and efficient water splitting system. Meanwhile, the photoelectrical conversion mechanism has been investigated in detail.     

Fabrication of dye-sensitized solar cells by transplanting highly ordered TiO2 nanotube arrays

Highly ordered TiO₂ nanotube arrays fabricated by anodization are very attractive to dye-sensitized solar cells (DSCs) due to their superior charge percolation and slower charge recombination. However, the efficiency of TiO₂-nanotube-based DSCs is 6.89%, which is still lower than that of TiO₂-nanoparticle-based DSCs. We have suggested the transplanting the highly ordered TiO₂ nanotube arrays to FTO glass to improve the performance of TiO₂-nanotube-based DSCs. DSCs based on transplanted TiO₂ nanotube arrays and TiO₂ nanoparticles were fabricated by same process and materials to exclude the unexpected factors. In TiO₂ thickness of ca. 15 μm, the efficiency of 2.91% in front-side illuminated DSCs based on TiO₂ nanotube arrays was higher than those in back-side illuminated DSCs based on TiO₂ nanotube arrays and in front-side illuminated DSCs based on TiO₂ nanoparticle. Front-side illuminated DSCs based on TiO₂ nanotube arrays having various thicknesses were successfully fabricated. The efficiency in DSCs having 20.0 μm thick TiO₂ nanotube arrays was improved to 5.36% by TiCl₄ treatment.     

Hydrogen production from sulphide wastewater using Ce3+–TiO2 photocatalysis

Cerium (Ce³⁺) doped TiO₂ powder was synthesized by a sol-gel method and characterized by Transmission Electron Microscope (TEM), X-ray Diffraction (XRD), UV–Vis Diffuse Reflectance Spectroscopy (UV-DRS), Fourier Transform Infrared Spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The Ce³⁺ doping strongly reduced the band gap of the TiO₂ from 3.2 eV (UV) to 2.7 eV (visible region). The photocatalytic activity of Ce³⁺ doped TiO₂ catalysts was evaluated by hydrogen production from sulphide wastewater under visible light illumination. The photocatalytic production of H₂ was studied in a batch recycle tubular photocatalytic reactor. The results show that 0.4% Ce³⁺–TiO₂ suspended in 500 mL of simulated sulphide wastewater irradiated at 150 W visible lamp produced maximum H₂ of 6789 μmol h^?1. It was noticed that the Ce³⁺ doped TiO₂ performs well than Nano TiO₂ and P25 TiO₂ photocatalysts.