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To enhance the activity of photocatalysts, it is crucial to use non-noble metal as a cocatalyst instead of noble metal in the arena of photocatalysis. In this study, to boost the photocatalytic hydrogen activity of pristine Zn 2 In 2 S 5 , XNi 2 P/ZIS 5 composite photocatalysts were prepared using noble-metal-free Ni 2 P as cocatalyst. Before photocatalytic hydrogen production experiments, the physicochemical properties of the synthesized materials were systematically characterized by advanced characterization methods. The experiment results demonstrate that the load of Ni 2 P cocatalyst can noticeably enhances the photocatalytic performance of Zn 2 In 2 S 5 and the photocatalytic hydrogen generation activities are observably influenced by the mass ratio of Ni 2 P to Zn 2 In 2 S 5. Among XNi 2 P/ZIS 5 , the 10Ni 2 P/ZIS 5 sample presents the optimal hydrogen production rate of 17.74 mmol g−1 h−1, which is 7.58 times as high as that of pristine Zn 2 In 2 S 5. The increased photocatalytic hydrogen evolution activity could be attributed to the introduction of noble-metal-free cocatalyst Ni 2 P, which serves as an electronic collector and reduction sites remarkably facilitates the separation and migration of photoexcited electrons of Zn 2 In 2 S 5. Meanwhile, the rate of reactions is significantly accelerated. • XNi 2 P/Zn 2 InS 5 composite photocatalysts were prepared by using noble-metal-free Ni 2 P as cocatalyst. • XNi 2 P/Zn 2 InS 5 composite photocatalysts demonstrate excellent H 2 evolution performance. • Ni 2 P facilitates the separation and migration of photoexcited electrons of Zn 2 In 2 S 5 and accelerates the rate of reactions. [ABSTRACT FROM AUTHOR]

The bifunctional electrocatalyst Ni 2 P/NF was synthesized for highly efficient oxidation of benzyl alcohol (BA) and reduction of water, simultaneously. [Display omitted] • Ni 2 P/NF (Ni foam) is fabricated by facile one-step calcination, and the nickel foam acts as both the support and the nickel source. • The catalyst Ni 2 P/NF is bifunctional and can be applied in the cathode and anode simultaneously. • A series of electrochemical tests show that Ni 2 P has excellent benzyl alcohol (BA) electrooxidation and HER activity. • The theoretical calculation explains that the synergistic effect of Ni and P can reduce the energy barrier of the rate-determining process during BA oxidation. Considering the high costs of producing catalysts, designing a bifunctional catalyst is one of the favorable ways through which the best result can be achieved with less effort. Herein, we use a one-step calcination method to obtain a bifunctional catalyst Ni 2 P/NF for the simultaneous oxidation of benzyl alcohol (BA) and reduction of water. A series of electrochemical tests have shown that this catalyst has a low catalytic voltage, long-term stability and high conversion rates. The theoretical calculation unveils the essential reason for its excellent activity. The synergistic effect of Ni and P optimizes the adsorption and desorption energy of the intermediate species, thus reducing the energy barrier of the rate-determining step during BA electrooxidation. Thus, this work has laid the foundation for designing a highly efficient bifunctional electrocatalyst for BA oxidation and the hydrogen revolution. [ABSTRACT FROM AUTHOR]

Summary: The photocatalytic hydrogen evolution of MnxCd1‐xS in pure water has been achieved through suitable modification methods and efficient co‐catalysts. This article presents the photocatalytic performance and reaction mechanism of a Ni2P‐modified P‐doped MnxCd1‐xS photocatalyst (PNIMCS). It possesses admirable photocatalytic H2 evolution ability both in pure water and trapping agent solutions. The co‐catalysts Ni2P and P doping make a significant contribution in facilitating the PNIMCS photocatalytic pure water splitting to hydrogen reaction. They make the ECB of PNIMCS more negative, lower the overpotential of the hydrogen evolution reaction, and also promote the separation and transfer of photogenerated h+ and e−, thus improving the hydrogen evolution performance of PNIMCS. [ABSTRACT FROM AUTHOR]

Summary: The photocatalytic hydrogen evolution of MnxCd1‐xS in pure water has been achieved through suitable modification methods and efficient co‐catalysts. This article presents the photocatalytic performance and reaction mechanism of a Ni2P‐modified P‐doped MnxCd1‐xS photocatalyst (PNIMCS). It possesses admirable photocatalytic H2 evolution ability both in pure water and trapping agent solutions. The co‐catalysts Ni2P and P doping make a significant contribution in facilitating the PNIMCS photocatalytic pure water splitting to hydrogen reaction. They make the ECB of PNIMCS more negative, lower the overpotential of the hydrogen evolution reaction, and also promote the separation and transfer of photogenerated h+ and e−, thus improving the hydrogen evolution performance of PNIMCS. [ABSTRACT FROM AUTHOR]

A facile two-step approach is employed to prepare novel Ni 2 P@CNT hybrid photocatalyst, which is assembled by nickel phosphide (Ni 2 P) nanoparticles on the inner wall of graphitic carbon nitride tube (CNT). This unique microstructure endows Ni 2 P@CNT with close interfacial interaction, promotes efficient separation of photoexcited charge carriers and provides enriched sites for photocatalytic reaction. Moreover, the hybrid system is found to exhibit more superior photocatalytic hydrogen evolution activity than pure CNT and Pt-decorated CNT (Pt@CNT). As a consequence, the work illustrates the essential role of experimental process on the final morphology and performance, which is expected to pave a new method to construct various kind of excellent photocatalyst. • Ni2P nanoparticles are anchored on the inner wall of g-C3N4 tube (CNT). • Performance of Ni 2 P@CNT is much higher than that of precious metal modified CNT. • Synthesis combines supramolecular self-assembly, impregnation and phosphorylation. [ABSTRACT FROM AUTHOR]

Abstract Ni2P has been decorated on CdS nanowires or nanorods for efficient photocatalytic H2 production, whereas the specific surface area remains limited because of the large size. Here, the composites of Cd0.5Zn0.5S quantum dots (QDs) on thin Ni2P porous nanosheets with high specific surface area were constructed for noble metal-free photocatalytic H2 generation. The porous Ni2P nanosheets, which were formed by the interconnection of 15–30 nm-sized Ni2P nanoparticles, allowed the uniform loading of 7 nm-sized Cd0.5Zn0.5S QDs and the loading density being controllable. By tuning the content of Ni2P, H2 generation rates of 43.3 μM h− 1 (1 mg photocatalyst) and 700 μM h− 1 (100 mg photocatalyst) and a solar to hydrogen efficiency of 1.5% were achieved for the Ni2P-Cd0.5Zn0.5S composites. The effect of Ni2P content on the light absorption, photoluminescence, and electrochemical property of the composite was systematically studied. Together with the band structure calculation based on density functional theory, the promotion of Ni2P in charge transfer and HER activity together with the shading effect on light absorption were revealed. Such a strategy can be applied to other photocatalysts toward efficient solar hydrogen generation.

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]

• g-C 3 N 4 nanosheets/Ni 2 P/Ni(PO 3) 2 ternary photocatalysts are prepared. • Ni 2 P/Ni(PO 3) 2 are decorated on the g-C 3 N 4 nanosheets uniformly. • It exhibits excellent visible-light-driven photocatalytic performance. • It is due to synergistic effect of earth-rich co-catalyst Ni 2 P/Ni(PO 3) 2 and g-C 3 N 4. Ni 2 P/Ni(PO 3) 2 /g-C 3 N 4 ternary 3D heterojunction photocatalysts are fabricated through the hydrothermal and calcination method. The prepared materials are characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectra and UV–vis diffuse reflection spectra. The obtained results show that the co-catalysts Ni 2 P/Ni(PO 3) 2 nanoparticles are dispersed on the surface of g-C 3 N 4 nanosheets uniformly. The visible-light-driven photocatalytic hydrogen production rate is up to 508.3 µmol h−1 g−1 with the assist of Pt cocatalyst, which is about 7 times and 5 times than pure g-C 3 N 4 and Ni 2 P/Ni(PO 3) 2 , respectively. It is worth noting that the photocatalytic degradation ratio of chlorophenols is also up to 95%. The obtained photocatalysts are stable even after several cycles, which is favorable for practical applications. The excellent photocatalytic performance can be ascribed to the formation of heterojunctions and the synergistic effect of earth-rich cooperative catalyst (co-catalyst) Ni 2 P/Ni(PO 3) 2 decorated the g-C 3 N 4 promoting the efficient separation of photogenerated electron–hole pairs. The as-prepared novel heterojunction photocatalysts have potential applications in fields of energy and environment, and this work also opens new windows for fabricating other high-performance photocatalysts. [ABSTRACT FROM AUTHOR]

Photocatalytic hydrogen evolution is considered as one of the promising pathways to settle the energy crises and environmental issues by utilizing solar energy. In this paper, noble-metal-free Ni2P was used as cocatalyst to enhance g-C3N4 for photocatalytic hydrogen production under visible light irradiation (λ > 420 nm). Characterization results indicated that Ni2P nanoparticles were successfully loaded onto g-C3N4, which can significantly contribute to accelerate the separation and transfer of photogenerated electron. The hydrogen evolution rate reached ∼ 270 µmol h−1 g−1 and the apparent quantum yield (AQY) was ∼ 2.85% at 420 nm. Meanwhile, there is no obviously decrease of the hydrogen production rate even after 36 h under visible light illumination. In addition, the mechanism of photocatalytic hydrogen evolution was also elaborated in detail.Graphical Abstract: [ABSTRACT FROM AUTHOR]

Abstract The development of a highly-efficient co-catalyst using earth-abundant elements is important to improve photocatalytic H 2 evolution. Herein, we prepared Ni 2 P-Zn 0.5 Cd 0.5 S (NPZCS) porous composites suitable for photocatalytic H 2 evolution under visible light irradiation. The in-situ synthesis and loading of Ni 2 P nanoparticles onto the porous structure of ZCS was achieved in one-step by a hydrothermal method without the addition of any surfactants or templates. It was revealed that porous ZCS exhibited advanced photocatalytic performance. Furthermore, the optimized NPZCS showed remarkably enhanced photocatalytic activity for H 2 evolution under visible light irradiation. An optimal H 2 evolution rate of 912.57 μmol•h−1 was observed over NPZCS loaded with 0.125% Ni 2 P, with a calculated apparent quantum efficiency of 37.5% at 420 nm. Loading of the Ni 2 P co-catalyst provided active reaction sites, boosted the efficiency of photoinduced electron-hole pair separation and extended the lifetime of photoinduced charge, resulting in enhanced photocatalytic H 2 evolution efficiency under visible light irradiation. Graphical abstract Image 1 Highlights • Ni 2 P-Zn 0.5 Cd 0.5 S photocatalyst was synthesized by a facile hydrothermal method. • Ni 2 P as a cocatalyst separates the electron-hole pairs efficiently. • Ni 2 P-Zn 0.5 Cd 0.5 S shows improved photoactivity in H 2 evolution via water splitting. [ABSTRACT FROM AUTHOR]

Non-noble-metallic Ni 2 P modified BiOBr with oxygen vacancy (O V) was synthesized by solvothermal method to construct novel O V -BiOBr/Ni 2 P nanoheterojunction. Compared with O V -BiOBr, the photoelectrochemical hydrogen evolution of O V -BiOBr/Ni 2 P was significantly improved. O V -BiOBr/Ni 2 P-2% showed the best hydrogen evolution rate of 455.34 μmol · cm−2 · h−1 without sacrificial agent, which was 5.94 times that of O V -BiOBr and 12.88 times that of pristine BiOBr. It was found that an appropriate amount of Ni 2 P loading enabled the closely contacted O V -BiOBr/Ni 2 P to have an optimal O V concentration, which realized the rapid electron-hole separation, simultaneously, the successful loading of Ni 2 P can effectively enhance the light absorption capacity. The formation of Bi-O-P chemical bond and nanoheterojunctions jointly promote electron transfer and inhibit carrier recombination. Density functional theory (DFT) calculations find that the hydrogen adsorption free energy of O V -BiOBr/Ni 2 P heterojunction is the lowest in this system. This study will provide some guidance for efficient photoelectrochemical hydrogen evolution without sacrificial agent. [Display omitted] • Concentration of oxygen vacancy can be regulated by Ni 2 P content in O V -BiOBr/Ni 2 P. • Bi-O-P chemical bond and O V -BiOBr/Ni 2 P heterojunction promote electron transfer. • O V -BiOBr/Ni 2 P displays boosting PEC hydrogen evolution without sacrificial agent. [ABSTRACT FROM AUTHOR]

Cocatalyst contributes to promote the separation and transfer of charge in photocatalytic system, which is an important factor to improve photocatalytic decomposition of water to produce hydrogen. Here, a simple and effective method to combine the main catalyst and the cocatalyst by a modified impregnation method is provided. A novel Ni 2 P/CdS is prepared by in-situ growth of Ni 2 P cocatalyst on the CdS surface using the modified impregnation method. The research shows that Ni 2 P, as an electron carrier, can promote the separation of electrons and holes, and significantly improve the photocatalytic activity of Ni 2 P/CdS. When Ni 2 P was 3% in Ni 2 P/CdS, the photocatalytic activity of hydrogen production was the highest, and the hydrogen production rate reached an astonishing 16.02 mmol h−1g−1 under visible light, which was 57 times that of CdS. Moreover, Ni 2 P/CdS photocatalyst has outstanding stability for hydrogen production. The mechanism of photocatalytic hydrogen production by Ni 2 P/CdS is proposed. [Display omitted] • A simple and effective method to combine the main catalyst and the cocatalyst by a modified impregnation method is provided. • Ni 2 P, as an electron carrier, can effectively promote the separation of electrons and holes. • The photocatalytic hydrogen evolution rate of 3% Ni 2 P/CdS is 57 times that of CdS, and it has outstanding hydrogen evolution stability. [ABSTRACT FROM AUTHOR]

Ni2P has been decorated on CdS nanowires or nanorods for efficient photocatalytic H2 production, whereas the specific surface area remains limited because of the large size. Here, the composites of Cd0.5Zn0.5S quantum dots (QDs) on thin Ni2P porous nanosheets with high specific surface area were constructed for noble metal-free photocatalytic H2 generation. The porous Ni2P nanosheets, which were formed by the interconnection of 15–30 nm-sized Ni2P nanoparticles, allowed the uniform loading of 7 nm-sized Cd0.5Zn0.5S QDs and the loading density being controllable. By tuning the content of Ni2P, H2 generation rates of 43.3 μM h− 1 (1 mg photocatalyst) and 700 μM h− 1 (100 mg photocatalyst) and a solar to hydrogen efficiency of 1.5% were achieved for the Ni2P-Cd0.5Zn0.5S composites. The effect of Ni2P content on the light absorption, photoluminescence, and electrochemical property of the composite was systematically studied. Together with the band structure calculation based on density functional theory, the promotion of Ni2P in charge transfer and HER activity together with the shading effect on light absorption were revealed. Such a strategy can be applied to other photocatalysts toward efficient solar hydrogen generation. [ABSTRACT FROM AUTHOR]