Photocatalytic Hydrogen Generation Research Articles

The nature of photocatalytic hydrogen generation on silicon nanowires prepared by MAWC

Highly n-doped silicon nanowires (SiNWs) exhibit excellent hydrogen generation. Our results indicate three hydrogen generation possibilities, i.e. SiNWs oxidation, photocatalysis and the cleavage of dangling H bonds, are jointly responsible for the efficient hydrogen generation. Oxidation accounts for about 80% of total hydrogen, photocatalysis contributes less than 20% of total hydrogen, and about 0.1% of total hydrogen is from cleavage of dangling H bonds. SiNWs were oxidized in water and form SiOx (0 < X < 2) thin layer. Furthermore, the ratio of photo-generated hydrogen to photo-generated oxygen is about 2.4:1. It suggests that photocatalysis appears to be a process of water splitting. This study is significant to reveal the mechanism of hydrogen production on SiNWs prepared by Metal-Assisted Wet Chemical Etching (MAWC).

Defect‐Rich Graphdiyne Quantum Dots as Efficient Electron‐Donors for Hydrogen Generation

AbstractDownsizing the graphdiyne (GDY) network to shape quantum dots (QDs) will provide attractive optical and electronic properties associated with quantum confinement and edge effects. Here, it is demonstrated that quantum confinement and defect introduction allow using GDY in donor–acceptor photocatalytic systems for solar‐to‐hydrogen conversion. The defect‐rich GDY QDs (GDYO‐QDs) exhibit a blue‐to‐green excitation‐dependent photoluminescence behavior, demonstrating their ability to harvest light over a wide energy range. Quantum‐chemical calculations evidenced an increase in the electronic bandgap of GDY upon quantum confinement and defect introduction without the appearance of trap states that can hamper charge transport properties. Such a unique optical behavior of QDs is used in photocatalytic hydrogen generation through the hybridization with TiO2 as a model photocatalyst. Theoretical and experimental results demonstrate that the donor−acceptor system tremendously boosts the photocatalytic performance, reaching 5288 µmol g−1 after 4 h of illumination at a constant rate of 1322 µmol g−1 h−1, using a low volume of a sacrificial electron donor (6% v/v). The QDs act as efficient chromophores harvesting UV and visible light while injecting electrons into the TiO2. This work opens a new area of using GDYO‐QDs as an efficient chromophore in developing donor–acceptor systems for photocatalysis and future photovoltaic devices.

Composites of Reduced Graphene Oxide and MAPbI3 Crystals for Photocatalytic Hydrogen Generation

Composites of Reduced Graphene Oxide and MAPbI₃ Crystals for Photocatalytic Hydrogen Generation

Novel room-temperature synthesis of pioneering CsPbX3@(Ce)UiO-66-Y hybrid nanomaterials for boosted photocatalytic hydrogen evolution

Perovskites are attractive structures for photocatalytic hydrogen generation, but also are limited by low stability, which can be improved by combination with other materials. Perovskite structures have potential for photocatalytic hydrogen generation; however, their practical application is hindered by inherent low stability. This limitation can be effectively mitigated through strategic combinations with complementary materials. Therefore, hybrids consisting of the perovskite CsPbX3 (X = Br, I) and the metal–organic framework (Ce)UiO-66-Y (Y = H, Br, NH2) were successfully synthesized for the first time, using a straightforward ligand-assisted reprecipitation synthesis at room temperature. To develop a room temperature synthesis for CsPbX3@(Ce)UiO-66-Y hybrid nanomaterials, herein, we optimized the synthesis of perovskite firstly (considering factors such as the choice of solvents, the drying of stabilizers, and the purification) and then developed an efficient way to combine both materials. Six types of hybrid materials, differing in the type of perovskite and functional group in the MOFs linker, were synthesized by the introduction of MOFs powder into a solution containing perovskite precursors (CsX and PbX2 in DMF stabilized by oleyamine and oleic acid) followed by antisolvent addition. We demonstrated that the hybrids containing perovskite in combination with MOF (Ce)UiO-66-NH2 in a molar ratio of 13:1 exhibited significantly higher activity and twice as long reaction stability time compared to the individual components of the hybrids when tested separately. This outcome underscores the presence of a synergistic effect, highlighting the potential of these hybrid materials in catalyzing hydrogen generation.

The enhancement of photocatalytic hydrogen production over Ag2WO4 modified g-C3N4 with Pt as cocatalyst

ABSTRACT The construction of heterojunction photocatalyst is an effective mean to improve the photoexcited electron–hole pair separation. The Ag2WO4-doped graphitic carbon nitride (g-C3N4, C3N4 for short) composite photocatalysts were fabricated by a simple calcination and in-situ depositing strategy. The composites were characterized by different techniques. The effects of Ag2WO4 content, type of scavengers, pH value of reaction solution and dose of scavenger on photocatalytic hydrogen (H2) generation were studied. It was found that the Ag2WO4 micro-nano particles were highly dispersed on the C3N4 surface. After doping Ag2WO4, the light absorption range of Ag2WO4-C3N4 material was broadened effectively from 440 nm to 448 nm, and the BET surface area of C3N4 was increased from 35.63 to 40.73 cm2·g−1, indicating that Ag2WO4 loading could provide some new BET surface areas. The binding energy of all elements in Ag2WO4-4/C3N4 was clearly shifted due to the charge transfer from C3N4 to Ag2WO4, implying a strong interaction between C3N4 and Ag2WO4. The photocatalytic H2 production rate of the optimized Ag2WO4-4/C3N4 was 6047.4 μmol·g−1·h−1, which was 2.04 and 171.8 times that of C3N4 and Ag2WO4, respectively. While Ag2WO4-4/C3N4 exhibited a poor H2 production performance in the absence of Pt co-catalyst (309.3 μmol·g−1·h−1), indicating the formation of heterojunction among Ag2WO4, C3N4 and Pt.

Highly efficient photocatalytic hydrogen generation of PtPdy nanoframe/2D-CdS: Shape-controlled preparation and property modulation

This work focuses on the structure design of Pt-based alloys, and their influences on 2D-CdS semiconductor photocatalyst in hydrogen (H2) generation reaction from water-splitting under visible light, using traditional experimental techniques and DFT calculations as Pd concave nanocube (Pd CNCs) as a template, PtPdx alloy with cuboctahedron core-shell structure (PtPdx NPs) and cuboctahedron nanoframe (PtPdy NFs) were successfully synthesized via wet chemical routes. The structure of Pt-based alloys was certified by XRD, HRTEM, XPS, and ICP. The Pt-based co-catalysts were photo-deposited on 2D-CdS in an aqueous solution of (NH4)2SO3 while the reaction for photo-generating of H2 occurred. The obtained photocatalysts show excellent activity towards hydrogen generation, i.e., in ascending order, Pd CNCs/2D-CdS (46.1 mmol/h/g) < PtPd1.8 NPs/2D-CdS (55.4 mmol/h/g) < PtPd0.2 NFs/2D-CdS (71.7 mmol/h/g, QE=61.46%, λ=420 nm). Photoelectrochemical tests, ESR, and work functions results indicate that PtPd0.2 NFs have excellent photoelectrochemical performance, the longest lifetime of electrons, and the highest work function, respectively. Moreover, DFT calculations unveil that PtPd0.2 has the largest surface energy and the lowest activation energy ΔGH* which results in the fast charge transfer rate at the PtPd0.2/2D-CdS interface. This work offers a novel thought into the structural design of Pt-based co-catalysts applied in photocatalytic hydrogen generation from water-splitting.

Efficient photocatalytic hydrogen production of Ni-Co layered double hydroxides (Ni-Co LDHs) anchored with reduced graphene oxide (rGO) hybrid composite

Using a suitable co-catalyst to boost photocatalytic H2 evolution from water splitting is crucial. Herein, we designed pristine NiCo-LDH and reduced graphene-oxide supported nickel-cobalt layered double hydroxide nanosheets (NiCo-LDH/rGO) as photocatalyst for the first time to evaluate the hydrogen production performance. Adding graphene has the potential to significantly increase electrical conductivity, and the supported NiCo-LDH has the potential to significantly reduce the likelihood of graphene self-aggregation. The effectiveness of its photocatalytic hydrogen generation was analyzed using a set of characterizations. The H2 evolution rates for pure rGO were 345.2 μmolh-1g-1, whereas those for Ni-Co LDH/rGO were 578.2 μmolh-1g-1. Average hydrogen generation per hour for the Ni-Co LDH/rGO composite material was 2032.1 μmolh-1g-1, which was 5.8 and 3.5 times that of rGO and Ni-Co LDH/rGO, respectively, NiCo-LDH@rGO's synergistic impact on the NiCo-LDH boosts the H2 generation pathway by increasing the catalyst's stability as well as performance by exposing active sites and speeding up electron transport. The produced nanocomposite shows excellent spatial charge separation and quicker electron transport across the conductive network of rGO, as shown by the photocurrent response test and photoluminescence (PL) spectra. The results of this study provide a fresh perspective on the practical use and synthesis of the inexpensive and effective NiCo-LDH/rGO, demonstrating the standard deviation of logical planning and preparation of high-performance photocatalysts.

Enhanced photocatalytic hydrogen generation using UiO-66(Zr) MOF with tailored modifications: A review

The utilization of UiO-66 MOF-based photocatalytic materials has achieved significant attention for their potential in hydrogen generation, owing to their remarkable stability and porous crystalline structure. Recent studies have disclosed enhanced light absorption capabilities in UiO-66 through both pre and post-synthetic modifications. These modifications also play a significant role in mitigating the recombination of photogenerated charge carriers by facilitating electron transfer in hybrid or derived materials. Designing of MOF-based modified improved photocatalyst includes, integration with other low band gap semiconductors, incorporation of noble metals as co-catalysts, surface engineering, inclusion of defects or introduction of heteroatom in the framework. MOF-COF hybridization, dye sensitization etc., further reinforced photocatalytic hydrogen yield. The above-mentioned comprehensive investigations have researched into aspects such as morphology, hydrogen generation efficiency, and the underlying mechanisms. It reveals that the creation of heterojunctions at interface channelizes the separation and smooth flow of electrons resulting in suppression of recombination reaction and favorable photocatalytic properties. The synergy between the components often results in enhanced performance. The present article provides a comprehensive review of modified UiO-66 MOF-based materials investigated for photocatalytic hydrogen generation.

In situ construction of the W18O49/Mn0.45Cd0.55S S-scheme heterojunction for enhanced photocatalytic hydrogen generation

Rapid compounding of semiconductor carriers is a crucial element limiting the performance of semiconductor photocatalytic decomposition of aqueous hydrogen, and the rational design of heterojunction is one effective method to improve the performance. In this paper, W18O49/Mn0.45Cd0.55S composite materials were prepared by basic hydrothermal and solvent-thermal strategy, additionally, S-scheme heterojunction was constructed between W18O49 and Mn0.45Cd0.55S by the analysis of the energy band structure. Furthermore, the W18O49/Mn0.45Cd0.55S-10 has excellent achievement and stability, and the photocatalytic production of hydrogen under visible light can reach up to 32.47 mmol g−1 h−1, which is 2.9 folds higher than Mn0.45Cd0.55S. The apparent quantum efficiencies (AQE) of Mn0.45Cd0.55S and W18O49/Mn0.45Cd0.55S-10 were 9.2 % and 16.5 %, respectively. The S-scheme heterojunction effectively ameliorates the space charge separation for W18O49 and Mn0.45Cd0.55S. This work may prove to be instructive for synthesizing remarkable performing S-scheme heterojunction photocatalysts.

Bifunctional S-scheme Fe7S8/CuIn5S8 heterostructures with S-vacancies for boosted photocatalytic antibiotic degradation and hydrogen evolution

The reasonable designing, interfacial tuning and construction of S-scheme heterostructures offering high performance water pollutants treatment and energy production still remains challenging. Following the structure, band structure and interface function perspective, we prepared Fe7S8/CuIn5S8 heterostructures photocatalysts with sulfur vacancies for superior norfloxacin (NOR) degradation and hydrogen production under visible light. In particular, for optimal 30FS/CIS (30%Fe7S8/CuIn5S8), the H2 evolution was up to 35.6 mmol g−1 h−1 which was 11.5 times than pristine Fe7S8 with TEOA as sacrificial agent. The heterojunction could also show 98.7% degradation of NOR in 90 min under visible light. Interestingly, using NOR pollutant as sacrificial agent under synergistic conditions, 22.7 mmol g−1 h−1 H2 evolution and 98.9% degradation of NOR (in 45 min) was achieved. The significantly boosted photocatalytic pollutant degradation and hydrogen generation performance over Fe7S8/CuIn5S8 hybrids is ascribed to the efficient S-scheme charge transfer and active sites provided by sulfur vacancies (Vs). The deep electron transfer mechanism and the charge transfer efficiency were supported by in-situ XPS, UPS, electrochemical experiments and photoluminescence. Experimental results including scavenging tests and ESR findings provided the direct evidence of photogenerated holes and ●OH radicals for pollutant degradation and electrons in hydrogen generation. This work contributes to effective designing and developing high-activity visible light/solar light assisted heterojunction photocatalysts for realizing superior clean energy generation and pollutant degradation.

Catalysing a sustainable future: Harnessing solar energy with novel Co3O4@VO2 nanocomposites for enhanced photocatalytic hydrogen generation and dye degradation

This study focuses on the hydrothermal synthesis and characterization of Concentration dependent Co3O4@VO2 nanocomposites with varying molar ratios of Co3O4 to VO2 (2:1, 1:1, and 1:2) for efficient hydrogen generation and dye degradation. The structural and morphological characteristics of the prepared nanocomposites were analysed using x-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). Crystallographic analysis using XRD confirmed the formation of crystalline Co3O4 with a monoclinic structure, while the presence of VO2 was identified by characteristic peaks in the XPS. Microscopic analysis using SEM and TEM revealed well-dispersed nanocomposites with nanoscale dimensions. Photocatalytic activities were evaluated for hydrogen evolution and dye degradation, with the nanocomposite featuring a 2:1 ratio of Co3O4 to VO2 (CV-21) demonstrating significantly enhanced performance. CV-21 exhibited a lower onset potential and higher current density for hydrogen evolution (2270μmol/h/g), indicating improved photocatalytic activity. Additionally, it displayed rapid and superior dye degradation (93% within 10 min) under sunlight compared to Victoria blue B (VBB) dye. The Co3O4@VO2 nanocomposites, particularly CV-21, demonstrate enhanced photocatalytic performance for hydrogen generation and dye degradation compared to pristine VO2 and Co3O4. This improvement possibly due to synergistic effects between Co3O4 and VO2, optimized structural characteristics, and improved interfacial properties in the nanocomposite structure. These findings highlight the promising potential of Co3O4@VO2 nanocomposites, particularly CV-21, for environmental remediation applications.

Photothermal and pyroelectric effects in hollow FeS2/CdS nanocomposites for enhanced photocatalytic hydrogen evolution

In this paper, a hollow structure of FeS2/CdS is designed to improve the photocatalytic generation of hydrogen by capitalizing on the synergistic interplay between the photothermal effect of FeS2 and the pyroelectric effect of CdS. The heat generated by the photothermal effect of FeS2 provides the hot end for the pyroelectric effect of CdS, and the condensate in the photocatalytic system provides the cold end. CdS undergoes spontaneous polarization and a thermoelectric impact in response to temperature fluctuations (ΔT), releasing surface charges. This process effectively governs the direction and rate of carrier migration within the FeS2 nanoparticles. The hydrogen production test demonstrates that FeS2/CdS-3 exhibited a hydrogen production rate of 154.0 μmol·g−1·h−1, which is 5.8 times higher than that of FeS2 (23.4 μmol·g−1·h−1), and it has excellent cycle stability. Furthermore, characterization through ultraviolet–visible spectroscopy, photoluminescence, electrochemical impedance spectroscopy, and linear sweep voltammetry confirms the outstanding carrier migration capability of the composite photocatalyst.

TiO2 nanorod decorated with MoS2 nanospheres: An efficient dual-functional photocatalyst for antibiotic degradation and hydrogen production

The design and preparation of dual-functional photocatalysts for simultaneously realizing photocatalytic wastewater purification and hydrogen energy generation pose significant challenges. This article presents the engineering of a binary heterostructured photocatalyst by combining TiO2 (nanorods) and MoS2 nanosphere using a straightforward solvothermal method and the assessment of the phase structures, morphologies, and optical properties of the resulting nanocomposites using diverse analytical techniques. The TiO2(Rod)/MoS2 composite exhibits remarkable efficacy in degrading ciprofloxacin, achieving 93% removal rate within 1 h, which is four times higher than that of bare TiO2. Moreover, the optimized TiO2(Rod)/MoS2 presents an outstanding hydrogen production rate of 7415 μmol g−1, which is ∼24 times higher than that of pristine TiO2. Under UV–visible light irradiation, the TiO2(Rod)/MoS2 heterojunction displays an exceptional photocatalytic performance in terms of both photodegradation and hydrogen production, surpassing the performance of TiO2 particle/MoS2. The study findings demonstrate that TiO2(Rod)/MoS2 nanocomposites exhibit considerably improved photocatalytic degradation and hydrogen generation activities. Based on the experimental results, a possible mechanism is proposed for the transfer and separation of charge carriers in Z-scheme heterojunctions.

Oxygen vacancy-rich high-pressure rocksalt phase of zinc oxide for enhanced photocatalytic hydrogen evolution

The generation of hydrogen as a clean energy carrier by photocatalysis, as a zero-emission technology, is of significant scientific and industrial interest. However, the main drawback of photocatalytic hydrogen generation from water splitting is its low efficiency compared to traditional chemical or electrochemical methods. Zinc oxide (ZnO) with the wurtzite phase is one of the most investigated photocatalysts for hydrogen production, but its activity still needs to be improved. In this study, an oxygen-deficient high-pressure ZnO rocksalt phase is stabilized using a high-pressure torsion (HPT) method, and the product is used for photocatalysis under ambient pressure. The simultaneous introduction of oxygen vacancies and the rocksalt phase effectively improved photocatalytic hydrogen production to levels comparable to benchmark P25 TiO2, due to improving light absorbance and providing active sites for photocatalysis without any negative effect on electron-hole recombination. These results confirm the high potential of high-pressure phases for photocatalytic hydrogen generation.

Dimensionally integrated nanoarchitectonics with Cu nanoparticles embedded in g-C3N4 nanosheets for efficient photocatalytic hydrogen generation and dye degradation

High-efficiency and sustainable non-noble metal cocatalyst can reduce the reaction barrier of photocatalysis or electrocatalysis to promote the hydrogen evolution reaction, which provides a feasible method for large-scale hydrogen production. A one-step thermal polymerization method was developed to successfully incorporate copper (Cu) into graphite nitride carbon (g-C3N4) through a mechanochemical pre-treatment and subsequently thermal polymerization. The synthesis controlling is a key to arrange the distribution of Cu nanoparticles in g-C3N4 nanosheets. Photocatalytic hydrogen generation tests were carried out for Cu incorporated g-C3N4 nanosheets obtained at different temperatures. Cu incorporated g-C3N4 at 680 °C (CCN-680) revealed the best H2 generation rate of 2985 μmol g-1 h−1, which was 12.7 times of that of pure g-C3N4 nanosheets obtained at same temperature. Furthermore, the degradation of methylene blue (MB) indicated that sample CCN-680-3 with optimized Cu ratio revealed enhanced performance, in which the degradation rate of MB increased from 80 to 97 % within 60 min. The introduction of Cu narrowed the band gap of g-C3N4 nanosheets, expanded light response in visible region, and finally improved greatly the separation efficiency of photogenerated charge carriers. These results are significant for highly efficient and stable photocatalysts.

Efficient hierarchical ZIF-based electro/photocatalyst toward hydrogen generation and evolution

In this study, a well-designed hierarchical BiFeO3/ZIF-67 (BFO-ZIF) composite was successfully synthesized to improve the performance of photocatalytic hydrogen generation in comparison to bare BiFeO3 and ZIF-67. Moreover, the behavior of the resultant electrocatalysts was also investigated in the hydrogen evolution reaction (HER). The synthesized electro-photocatalysts were characterized by various physical and photo/electrochemical analyses. The remarkable outcomes of the composite with 50 wt% of ZIF-67 in hydrogen generation correspond to the high specific surface area of the photocatalyst concurrently with the formation of active sites and new charge channels, leading to a modified charge transfer pathway and lower electron-hole recombination. The maximum H2 generation rate over the optimal BFO-ZIF composite (BFO-ZIF(50)) attained 1617 μmol g−1 h−1 during visible light exposure, surpassing the rates observed for pure BFO and ZIF-67. Furthermore, the BFO-ZIF(50) electrocatalyst, with the onset potential of −0.089 V, resulted in an overpotential of −0.19 V at a current density of 10 mA cm−2, while a Tafel slope of 81.6 mV dec−1 in 1.0 M KOH showed the highest activity. The elevated photocatalytic hydrogen generation and improved HER performance of the developed catalysts signify a synergistic effect resulting from the junction and the Z-scheme charge transfer mechanism between the ZIF-67 and BFO nanomaterials. This introduces the BFO-ZIF composite as an efficient photocatalyst and electrocatalyst for hydrogen generation and evolution reaction.

Coupling Reliable Interfacial Carrier Migration Channels with Visible-Light Response Antennas in ZnO-Based Heterostructure for Ameliorated Photocatalytic Hydrogen Generation.

Engineering targeted and reliable charge transfer pathways in multiphase photocatalysts remains a challenge. Herein, we conceptualize the Cd@CdS-ZnO/reduced graphene oxide (rGO)/ZnS heterostructures coupled with reliable carrier migration channels and visible-light response antennas by building rGO-integrated electrochemical nanoreactors and an ion-exchange process. In this ternary catalyst, the Cd clusters and rGO perform as charge relays to boost carrier transport via the Z-scheme route and accelerate photogenerated carriers to react with surface-adsorbed substances. Meanwhile, thanks to CdS, the heterostructures have photocatalytic properties under visible light illumination and can also inhibit self-corrosion by shielding Cd clusters to avoid disrupting charge transfer channels. Therefore, the special heterostructure demonstrates fascinating photocatalytic hydrogen production activity without the intervention of cocatalysts. This work provides a feasible protocol for improving the interfaces between metals and semiconductors to achieve efficient photocatalytic hydrogen generation.

Time-Dependent synthesis of ZnS and its influence on photocatalytic hydrogen generation

This study explores the impact of varied synthesis times on the properties and performance of zinc sulfide (ZnS) in the photocatalytic hydrogen production. Validating the synthesis of ZnS from hydrozincite, our investigation extends to diverse solvothermal synthesis durations (0.5, 5, 24 and 72 h). X-ray diffraction analyses confirm a direct correlation between synthesis time and crystallite size growth. Mesoporosity and consistent functional groups characterize all materials. Prolonged synthesis times induce ethylenediamine-Zn2+ complexes, elevating defect density and causing a red shift in materials, impacting electronic structure and reducing band gap. Paradoxically, extended synthesis times correlate with diminished hydrogen production, emphasizing the role of surface area over electronic properties in photocatalytic performance. The 05H catalyst produces an average of 2.11 times more hydrogen than 24H and 72H catalysts with a hydrogen production rate of 276 µmolg−1h−1 The study underscores the intricate interplay of parameters, providing insights into achieving optimal photocatalytic performance.

Bimetallic CuCo nanoparticles optimized hydrogen generation active centers thereby significantly enhancing TiO2 photocatalytic activity

Bimetallic nanostructures are currently a hot pot material among many hydrogen generation co-catalysts. In this study, CuCo bimetallic nanostructures were formed by introducing Co into Cu as the co-catalyst for TiO2. Characterization results from XRD, XPS, and TEM indicated the successful preparation of the high-crystallinity, impurity-free CuCo/TiO2 photocatalyst, with CuCo bimetallic nanoparticles uniformly dispersed on TiO2. After the addition of Co, density functional theory (DFT) calculations showed that the free energy of H adsorption on the Cu site was optimized from 0.27 eV to −0.56 eV, which was beneficial for hydrogen production from TiO2. Electrochemical characterization, photoluminescence (PL) spectroscopy, infrared (IR) thermography, and finite difference in time domain (FDTD) results showed that the bimetallic CuCo acted as the co-catalyst, which increased the temperature of the reaction system, facilitated the separation of light-generated electron-hole pairs, and accelerated the charge transfer, thus promoting the photocatalytic hydrogen generation. The findings of the photocatalytic performance demonstrate that the photocatalyst exhibits the H2 generation rate of 1933.8 μmol/g/h, which is approximately 9 times greater than that of pure TiO2 (213.4 μmol/g/h), when the bimetallic CuCo is loaded in the molar ratio of 5:5 and at the loading amount of 2 wt%. Additionally, the photocatalyst demonstrated excellent catalytic stability, reaching 87.1% of the initial after 16 h of cycling tests. It is foreseen that further study and optimization of various metal couplings may enable the larger widespread application of bimetals as co-catalysts for hydrogen generation.

Efficient photocatalytic hydrogen generation by CeCO3OH/TiO2 composites

Due to its low photogenerated carrier separation efficiency and wide band gap, the photocatalytic activity of TiO2 is not ideal. In this work, CeCO3OH/TiO2 composites were successfully prepared by a simple hydrothermal method. A series of characterisations shows that the CeCO3OH/TiO2 composites improves the photogenerated carrier separation efficiency, narrowes the band gap width and increases the visible light absorption capacity compared with the monomer, enhancing the photocatalytic hydrogen evolution performance. Under visible light irradiation, 20% CeCO3OH/TiO2 exhibites the highest photocatalytic hydrogen production performance of 2386.16 μmol g−1 h−1, which is 18.7 times higher than that of pure TiO2 and 25.8 times higher than that of pure CeCO3OH. It provides ideas for the development of more efficient photocatalytic materials and technologies.