Cadmium sulfide (CdS)-based photocatalysts have attracted extensive attention owing to their strong visible light absorption, suitable band energy levels, and excellent electronic charge transportation properties. This review focuses on the recent progress related to the design, modification, and construction of CdS-based photocatalysts with excellent photocatalytic H 2 evolution performances. First, the basic concepts and mechanisms of photocatalytic H 2 evolution are briefly introduced. Thereafter, the fundamental properties, important advancements, and bottlenecks of CdS in photocatalytic H 2 generation are presented in detail to provide an overview of the potential of this material. Subsequently, various modification strategies adopted for CdS-based photocatalysts to yield solar H 2 are discussed, among which the effective approaches aim at generating more charge carriers, promoting efficient charge separation, boosting interfacial charge transfer, accelerating charge utilization, and suppressing charge-induced self-photocorrosion. The critical factors governing the performance of the photocatalyst and the feasibility of each modification strategy toward shaping future research directions are comprehensively discussed with examples. Finally, the prospects and challenges encountered in developing nanostructured CdS and CdS-based nanocomposites in photocatalytic H 2 evolution are presented.

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Efficient H2O splitting for H2 evolution over the semiconductor photocatalyst is a crucial strategy in the field of energy and environment. Herein, cocatalyst‐free 2D–2D CdS/g‐C3N4 step‐scheme (S‐scheme) heterojunction photocatalysts are fabricated through in situ hydrothermal growth of 2D CdS nanosheets (NSs) on 2D g‐C3N4 NSs. The results clearly confirm that the binary CdS/0.7g‐C3N4 S‐scheme heterojunction shows the best H2 production rate (15.3 mmol g−1 h−1) without using any cocatalyst, which is 3.83 times and 3060 times higher than those of pure CdS and g‐C3N4, respectively. The apparent efficiency of CdS/0.7g‐C3N4 at 420 nm is 6.86%. Importantly, the as‐prepared CdS/0.7g‐C3N4 S‐scheme heterojunction has good stability when continuously irradiated for 21 h. The improved stability and activity are attributed to the formation of the S‐scheme heterojunction, which can markedly accelerate the interfacial charge separation for surface reaction. It is expected that the design of robust cocatalyst‐free CdS/g‐C3N4 2D–2D S‐scheme heterojunction can become a promising approach to develop the highly active H2 evolution systems based on various kinds of conventional semiconductor NSs.

Developing an inexpensive and high-efficiency hydrogen-production cocatalyst to replace the noble metal Pt remains a big challenge in the fields of sustainable photocatalytic hydrogen evolution. Herein, we report the exploration of a high-efficiency binary noble-metal-free Cu3P-CNT H2-evolution cocatalyst by direct high-temperature phosphatizing of Cu­(OH)2-CNT. Impressively, combining the advantages of noble-metal-free Cu3P and carbon nanotube (CNT), the binary Cu3P-CNT cocatalysts show high-efficiency photocatalytic H2 evolution in Eosin Y (EY)-containing semiconductor-free photocatalytic systems. The maximum visible-light H2-generation rate for promising EY-Cu3P-CNT systems was 17.22 mmol g–1 h–1. The highest apparent quantum efficiency (AQE) could reach 10.23% at 500 nm. More importantly, we found that the separation of photogenerated electrons and holes in the Eosin Y, the efficiency of electron transfer from EY to the active edge sites of Cu3P, and the electrocatalytic H2-evolution activity of Cu3P could be simultaneously boosted via readily adding the conductive CNT, thus achieving the significantly improved photocatalytic H2 evolution. This work provides a simple and facile strategy to design highly efficient semiconductor-free photocatalytic proton-reduction systems using high-activity transition metal phosphides and inexpensive carbon nanomaterials.

Cation doping is often used to stabilize the cubic or tetragonal phase of zirconia for enhanced thermomechanical and electrochemical properties. In the present paper we report a combined density functional theory (DFT) and molecular dynamics study of the effect of Sc, Y, and Ce dopants on properties of Ni/[Formula: see text] interfaces and nickel sintering. First, we develop an MD model that is based on DFT data for various nickel/zirconia interfaces. Then, we employ the model to simulate Ni nanoparticles coalescing on a zirconia surface. The results show the possibility of particle migration by means of fast sliding over the surface when the work of separation is small (<[Formula: see text]). The sliding observed for the O-terminated Ni(1 1 1)/[Formula: see text](1 1 1) interface is not affected by dopants in zirconia because the work of separation of the doped interface stays small. The most pronounced effect of the dopants is observed for the Zr-terminated Ni(1 1 1)/[Formula: see text](1 1 1) interface, which possesses a large work of separation ([Formula: see text]) and thus restricts the sliding mechanism of Ni nanoparticle migration. DFT calculations for the interface revealed that dopants with a smaller covalent radius result in a larger energy barriers for Ni diffusion. We analyze this effect and discuss how it can be used to suppress nickel sintering by using the dopant selection.