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To improve the photocorrosion of CdS nanorod arrays (CdS NRAs), we have designed a simple and facile treatment method of in-situ hydrogenation to fabricate CdS@SnS/SnO 2 heterostructure on fluorine-doped tin oxide glass, which is a highly photostable hydrogenated CdS-based film photocatalyst (CdS NRAs-H 2 ). Over a 25-h long time irradiation, the total photocatalytic hydrogen production of hydrogenated CdS NRAs is almost 2.0 times higher than that of un-hydrogenated CdS NRAs. Moreover, the average hydrogen production rate of CdS NRAs-H 2 can steadily maintain at 23.75 μmol cm −2 h −1 with 102% of retention rate after 5 reaction cycles, while they are only 6.13 μmol cm −2 h −1 with 30% of retention rate for un-hydrogenated common CdS NRAs. The photocatalytic mechanism on enhanced activity and stability for hydrogenated CdS NRAs photocatalyst is also investigated and discussed in detail. [ABSTRACT FROM AUTHOR]

An efficient Ni 2 P–CdS photocatalyst for photocatalytic hydrogen evolution was synthesized by phosphorizing β-Ni(OH) 2 nanosheet with exposed (001) facets on CdS nanorods. The obtained Ni 2 P–CdS composite displays an outstanding and stable photocatalytic hydrogen generation rate of 68.47 mmol g−1 h−1 in 10 vol% lactic acid under visible light irradiation, more than 17 times higher than that for pure CdS nanorods. The transient photocurrent response, EIS measurement, Mott-Schottky plots, acidic LSV measurement, and PL spectra have proved that Ni 2 P loading can significantly improve the separation of photo-excited electron-hole pairs in CdS nanorods and enhance the hydrogen evolution capability for CdS. These improvements are achieved by features of Ni 2 P such as the high capability of trapping photo-generated electrons from CdS, lifting the total Fermi level and lowering the hydrogen evolution overpotential of the composite. The results show that β-Ni(OH) 2 precursor with a high exposure degree of (001) facet is contributed to the epitaxial formation of (001)-facet-exposed Ni 2 P co-catalyst on CdS nanorods, resulting in that the Fermi level and the hydrogen evolution overpotential of the composite can be further lifted and lowered. This study has provided a novel precursor-derived route to fabricate high-performance co-catalysts with highly exposed active facets on CdS nanorods for effective photocatalytic hydrogen evolution. • Ultrathin β-Ni(OH) 2 nanosheet precursor is employed in fabricating Ni 2 P on CdS. • β-Ni(OH) 2 nanosheet with exposed (001) facet facilitate Ni 2 P(001) growth on CdS. • Hydrogen evolution and charge separation of CdS can be markedly improved by Ni 2 P. [ABSTRACT FROM AUTHOR]

The substitution of noble metal platinum catalyst is one of the important research contents for sustainable development and is also the key to the practical application of photoelectrochemical (PEC) hydrogen production. In this work, we loaded the 1T-2H mixed phase MoS 2 on the hydrogenated anatase/rutile heterophase TiO 2 (A-H-RTNA) by hydrothermal method to prepare a new MoS 2 /A-H-RTNA electrode material. The prepared material exhibited higher carrier density, lower PL intensity and higher conductivity than Pt/A-H-RTNA because 1T-MoS 2 has more active sites and lower charge transfer resistance than Pt. With the bias voltage of −0.4 V, the optimized 16MoS 2 /A-H-RTNA as photocathode shows the largest PEC hydrogen production rate of 1840 mmol m−2 h−1, which is 2.9 and 2.2 times higher than those of A-H-RTNA (625 mmol m−2 h−1) and Pt/A-H-RTNA (848 mmol m−2 h−1), respectively. We innovatively used the prepared 16MoS 2 /A-H-RTNA film as counter electrode instead of Pt electrode to construct a PEC system without any noble-metal. The result demonstrates that the noble-metal-free MoS 2 loaded on TiO 2 electrode as counter electrode has 75% PEC activity of noble metal Pt electrode. This study develops a PEC method for hydrogen evolution, which no longer depends on precious metal platinum as cathode. A new MoS 2 /A-H-RTNA electrode with 2 times higher hydrogen production rate than Pt/A-H-RTNA was prepared by loading MoS 2 on the hydrogenated TiO 2 heterostructure film. The prepared MoS 2 /A-H-RTNA film was used as photocathode instead of Pt electrode to construct an innovative and efficient PEC system without any noble-metal. Image 1 • MoS 2 is loaded on hydrogenated anatase/rutile TiO 2 heterophase structure (A-H-RTNA). • MoS 2 /A-H-RTNA has low charge transfer resistance for photoelectrochemical (PEC) reaction. • MoS 2 /A-H-RTNA as photocathode has 2 times higher PEC hydrogen production rate than Pt/A-H-RTNA. • MoS 2 /A-H-RTNA film can be used as photocathode instead of Pt electrode. • An innovative and efficient PEC system without any noble metal is constructed. [ABSTRACT FROM AUTHOR]

A facile method of loading CoS x nanosheet onto CdS nanorod has been designed, and the prepared CdS-CoS x composite catalyst exhibited significantly improved performance for photocatalytic hydrogen evolution compared with CdS catalyst. This composite catalyst was also used as a photoanode for photoelectrochemical (PEC) hydrogen production. The hydrogen production rate reached 168.6 μmol cm−2 h−1 (37.77 L m−2 h−1) under the simulated solar light, which is 2.7 times that of CdS and the same as that of CdS–Pt. In addition, in the Na 2 S–Na 2 SO 3 system for PEC hydrogen production, an abnormal relationship between photocurrent and the hydrogen production yield was found. By designing a series of experiments, the photocatalytic and photoelectrochemical characteristics for hydrogen production were reasonably revealed for the first time. In this work, the prepared structured catalyst is easy to be recycled, and CoS x can replace precious metal Pt, showing a promising application. Image 1 • CoS x as co-catalyst is loaded on CdS nanorod by a facile method. • CdS-CoS x has good activity and stability for photoelectrochemical (PEC) reaction. • PEC activity of CdS-CoS x as photoanode for H 2 production is the same as that of CdS–Pt. • An abnormal relationship between photocurrent and hydrogen production is found. • The reaction network in Na 2 S–Na 2 SO 3 system for PEC H 2 production is proposed. [ABSTRACT FROM AUTHOR]

Photocatalytic water splitting into hydrogen is a very attractive and desirable technology to realize sustainable and renewable green energy conversion. Up to now, many research results have confirmed that cocatalyst such as Pt is essential for a high efficiency photocatalytic H 2 evolution system. In a traditional view, the cocatalyst should be closely combined with the photocatalyst to achieve a high H 2 or O 2 photo-productive rate. In this work, an unusual point has been put forward that the suitable loading position of cocatalyst Pt for film-type TiO 2 catalyst is on the bare Fluorine-doped tin oxide (FTO) substrate instead of on the surface of TiO 2 in the electrolyte solutions. Especially, in acidic electrolyte, the hydrogen production rate of this new designed catalyst with Pt loaded on FTO (TiO 2 -Pt/FTO) reaches 2.4 times that of the common catalyst with Pt loaded on TiO 2 (Pt/TiO 2 -FTO). According to the experiment results, it is supposed that this loading way of cocatalyst on the substrate can construct a self-bias photocatalytic electrochemical cell system, drive electrolyte ions' movement directionally, and obtain high photocatalytic H 2 production efficiency. The universality of this innovation has been verified by CdS and CdS@TiO 2 film-type catalysts. This study provides a new guide in exploring high-efficiency film-type photocatalytic system for water splitting into hydrogen in the electrolyte solution. [ABSTRACT FROM AUTHOR]

CuO 1− x cluster-modified TiO 2 (CuO 1− x /TiO 2 ) photocatalysts were prepared by an in-situ photoreduction deposition of Cu on TiO 2 powder support using copper acetate as a Cu source. The prepared samples without any Pt co-catalyst present an especially high photocatalytic H 2 -evolution activity under solar light irradiation with 5% glycerol as sacrificial agent. The optimal CuO 1− x /TiO 2 catalyst with only 1 wt% CuO 1− x exhibits a high activity of 1725 μmol h −1 g −1 for H 2 evolution, which reaches 120 times that of TiO 2 . The high photocatalytic activity of H 2 production is attributed to the highly dispersed CuO 1− x nano clusters on the surface of the TiO 2 . In addition, Pt/CuO 1− x /TiO 2 was also prepared by loading Pt on CuO 1− x /TiO 2 sample, and its photocatalytic hydrogen evolution activity is enhanced 1.8 times compared with that of Pt/TiO 2 for overall water splitting reaction under solar light, demonstrating that a small amount CuO 1− x wondrously improves the photocatalytic activity of Pt/TiO 2 for overall water splitting reaction. This paper reports an economic and simple approach to prepare a photocatalyst with high hydrogen-production activity. [ABSTRACT FROM AUTHOR]

In recent years, tremendous efforts have been devoted to develop new photocatalyst with wide spectrum response for H 2 generation from water or aqueous solution. In this work, CdS nanoparticles (NPs) have been immobilized on hydrogenated three-dimensional (3D) branched TiO 2 nanorod arrays, resulting in a highly efficient photocatalyst, i.e, CdS/H-3D-TiO 2 . In addition, electrochemical reduction of H + ion is identified as a limiting step in the photocatalytic generation of H 2 at this catalyst, while here a Pt wired photocatalysis system (CdS/H-3D-TiO 2 /Pt-wire) is designed to overcome this barrier. Without the application of potential bias, visible light photocatalytic hydrogen production rate of CdS/H-3D-TiO 2 /Pt-wire is 18.42 μmol cm −2 h −1 , which is 11.2 times that of CdS/H-3D-TiO 2 without Pt (1.64 μmol cm −2 h −1 ). The Pt wire acts as an electron super highway between the FTO substrate and H + ions to evacuate the generated electrons to H + ions and catalyze the reduction reaction and consequently generate H 2 gas. This work successfully offers a novel direction for dramatic improvement in H 2 generation efficiency in photocatalysis field. [ABSTRACT FROM AUTHOR]

Two kinds of branched hydrogenated TiO 2 nanorod arrays, i.e., hydrogenated TiO 2 nanorod supported hydrogenated TiO 2 branch arrays (H-BTNRs) and hydrogenated TiO 2 nanorod supported unhydrogenated TiO 2 branch arrays (B/H-TNRs), have been successfully designed and prepared by a facile approach. Under simulated solar light, the prepared B/H-TNRs have the highest hydrogen evolution rate of 6.65 μmol cm −2 h −1 , which is 4.7 and 2.4 times those of hydrogenated TiO 2 nanorod arrays (H-TNRs) and H-BTNRs, respectively. This study indicates that the heterostructure design of the unhydrogenated TiO 2 branch and hydrogenated TiO 2 nanorod promotes the separation of charge carries on the interface and enhances photocatalytic hydrogen evolution. [ABSTRACT FROM AUTHOR]

The hierarchical Ag NPs with a bimodal size distribution were auto-decorated on the surface of rice-like N-TiO 2 (named h-Ag/N-TiO 2 ) by semiconductor-metal double excitation process under solar light irradiation. The photoinduced growth process of self-assembled h-Ag/N-TiO 2 and its photocatalytic mechanism of photo-splitting ethanol into hydrogen have been discussed in detail. The synthesized h-Ag/N-TiO 2 as a plasmonic photocatalyst for photo-splitting ethanol exhibited a higher hydrogen production rate (4.7 mmol h −1 g −1 ) than Ag NPs universally loaded N-TiO 2 (3.4 mmol h −1 g −1 ) and pure N-TiO 2 (2.1 mmol h −1 g −1 ). This work presents a reversed photo-induced synthesis strategy to design a stable Ag-TiO 2 plasmonic photocatalyst with high photocatalytic efficiency under solar light. A better understanding of this solar light induced self-assembled process for Ag-TiO 2 is crucial in developing metal-semiconductor system for solar energy materials. [ABSTRACT FROM AUTHOR]

Abstract: The influence of the electrodeposition potential on the morphology of Cu2O/TiO2 nanotube arrays (Cu2O/TNA) and their visible-light-driven photocatalytic activity for hydrogen evolution have been investigated for the first time in this work. The photocatalytic hydrogen evolution rate of the as-prepared Cu2O/TNA at the deposition potential of −0.8 V was about 42.4 times that of the pure TNA under visible light irradiation. This work demonstrated a feasible and simple electrodeposition method to fabricate an effective and recyclable visible-light-driven photocatalyst for hydrogen evolution. [Copyright &y& Elsevier]

Abstract: Cu(OH)2/TNAs photocatalyst was prepared by loading Cu(OH)2 nanoparticles on TiO2 nanotube arrays (TNAs) using a chemical bath deposition method. The amount of Cu(OH)2 loaded on the arrays was controlled by the repeated deposition times. The prepared catalyst was used to generate hydrogen under simulated solar light irradiation, and the results demonstrated that the hydrogen yield of Cu(OH)2/TNAs was 20.3 times that of the pure TNAs. Furthermore, the photocatalytic efficiency for hydrogen production decreased only 5.8% after five cycles, indicating that Cu(OH)2/TNAs photocatalyst showed excellent stability and reusability. This work presents an applicable and facile method to fabricate a highly active and stable photocatalyst for hydrogen production. [Copyright &y& Elsevier]