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In this paper, Cu-Zr alloy powders and materials with different Zr contents were prepared by horizontal stirring high-energy ball milling combined with vacuum hot-pressing sintering. The results show that the mechanical alloying time of Cu-5%Zr, Cu-10%Zr and Cu-15%Zr alloy powder prepared by high energy ball mill is 7 h, 14 h and 22 h, respectively. At the beginning of high-energy ball milling, Zr particles adhere to the Cu matrix and agglomerate phenomenon occurs. With the progress of ball milling, the powder particles become smaller, the Zr particles gradually distribute evenly and widely on the surface of the Cu matrix, and are dissolved in the Cu matrix, and finally alloying is achieved. Cu-Zr alloys with different Zr content are prepared by vacuum hot pressing sintering. When Zr content is 10%, the maximum hardness of Cu-Zr alloy is 277.24HV, which is 462% higher than that of pure copper. [ABSTRACT FROM AUTHOR]

Exploiting an efficient and noble-metal-free cocatalyst is highly desired for photocatalytic H 2 evolution from water. Here, we synthesized the MoS 2 -RGO/ZnO composite photocatalysts via a facile two-step solvothermal process. Through optimizing of the MoS 2 and reduced graphene oxide (RGO) cocatalyst component proportion, the 0.75 wt%5G95 M/ZnO composite photocatalyst shows the highest H 2 production rate of 288.4 μmol g −1 h −1 when the amount of MoS 2 -RGO is 0.75 wt% and the weight ratio of RGO to MoS 2 is 5:95, which is about 14.1 times higher than the pure ZnO. More importantly, the ternary MoS 2 -RGO/ZnO composite photocatalyst exhibits much higher H 2 evolution activity than the Pt loaded ZnO under the same condition. The significant improvement in the H 2 evolution activity is ascribed to the positive synergetic effect between MoS 2 and RGO, which acts as a hydrogen evolution cocatalyst and a robust electron transport pathway, respectively. This study suggests that MoS 2 -RGO can serves as an efficient and noble-metal-free cocatalyst to improve the H 2 production performance of ZnO by suppressing the electron-hole pairs recombination. [ABSTRACT FROM AUTHOR]