Telluriums (Te) with various nanostructures, including particles, wires, and sheets, are controllably synthesized by adjusting the content of polyvinylpyrrolidone (PVP) in a facile solvothermal reaction. Te nanostructures all have complete grain sizes with excellent crystallinity and mesopore structures. Further, the formation mechanisms of Te nanostructures are proposed to be that the primary nuclei of Te are released from the reduction of TeO₃²⁻ using N₂H₄·H₂O, and then grow into various nanostructures depending on the different content of PVP. These nanostructures of Te all exhibit the photocatalytic activities for the degradation of MB and H₂ production under visible light irradiation, especially Te nanosheets, which have the highest efficiencies of degradation (99.8%) and mineralization (65.5%) at 120 min. In addition, compared with pure Te nanosheets, the rate of H₂ production increases from 412 to 795 μmol∙h⁻¹∙g⁻¹ after the introduction of Pt, which increases the output by nearly two times. The above investigations indicate that Te with various nanostructures is a potential photocatalyst in the field of degradation of organic pollutants and H₂ fuel cells.

A Cu(OH)₂/Ni₃S₂ composite has been designed and in situ constructed on Cu foam substrate by facile two-step electrodeposition. Cu(OH)₂ is achieved on Cu foam by galvanostatic electrodeposition, and the subsequent coating of Ni₃S₂ is realized by cyclic voltammetric (CV) electrodeposition. The introduction of Cu(OH)₂ provides skeleton support and a large specific surface area for the Ni₃S₂ electrodeposition. Benefiting from the selection of different components and preparation technology, the Cu(OH)₂/Ni₃S₂ composite exhibits enhanced electrochemical properties with a high specific capacitance of 4.85 F cm⁻² at 2 mA cm⁻² and long-term cyclic stability at 80.84% (4000 cycles).

Developing efficient catalysts to produce clean fuel by using solar energy has long been the goal to mitigate the issue of traditional fossil fuel scarcity. In this work, we design a heterostructure photocatalyst by employing two green components, Ni(OH)₂ and ZnIn₂S₄, for efficient photocatalytic H₂ evolution under the illumination of visible light. After optimization, the obtained photocatalyst exhibits an H₂ evolution rate at 0.52 mL h⁻¹ (5 mg) (i.e., 4640 μmol h⁻¹ g⁻¹) under visible light illumination. Further investigations reveal that such superior activity is originated from the efficient charge separation due to the two-dimensional (2D) structure of ZnIn₂S₄ and existing high-quality heterojunction.

In this study, we rationally designed a facile stepwise route and successfully synthesized a Co(OH)₂/Ni₃S₂ heterostructure supported on nickel foam (NF) as a binder-free electrode for energy storage. Galvanostatic deposition was first applied to produce uniform Co(OH)₂ nanoflakes on NF. Then, Ni₃S₂ was applied to its surface by potentiostatic deposition to form a Co(OH)₂/Ni₃S₂ heterostructure at room temperature. The added Co(OH)₂ not only functions as a practical electrochemically active component but also provides support for the growth of Ni₃S₂, and the deposition amount of Ni₃S₂ is controlled by adjusting the electrodeposition duration of Ni₃S₂. Then, the electrochemical behaviors of the Co(OH)₂/Ni₃S₂ composite can be optimized. A maximum areal specific capacitance (Cs) of 5.73 F cm⁻² at 2 mA cm⁻² was achieved, and the coulombic efficiency was as high as 94.14%. A capacitance retention of 84.38% was measured after 5000 charge–discharge cycles.

The ZnO/Ni₂S₃ composite has been designed and in situ synthesized on Ni foam substrate by two steps of electrodeposition. ZnO was achieved on Ni foam by a traditional potentiostatic deposition, followed by cyclic voltammetric (CV) electrodeposition, to generate Ni₂S₃, where the introduction of ZnO provides abundant active sites for the subsequent Ni₂S₃ electrodeposition. The amount of deposit during CV electrodeposition can be adjusted by setting the number of sweep segment and scan rate, and the electrochemical characteristics of the products can be readily optimized. The synergistic effect between the ZnO as backbones and the deposited Ni₂S₃ as the shell enhances the electrochemical properties of the sample significantly, including a highly specific capacitance of 2.19 F cm⁻² at 2 mA cm⁻², good coulombic efficiency of 98%, and long-term cyclic stability at 82.35% (4000 cycles).

The Ag/Ni(OH)2 composite electrode has been designed and in situ constructed on a copper substrate by combining electroless deposition technology with electrodeposition. The products can be directly used as a high performance binder free electrode. The synergistic effect between the Ag nanocubes (AgNCs) as backbones and the deposited Ni(OH)2 as the shell can significantly improve the electrochemical properties of the composite electrode. Moreover, this in situ growth strategy forms a strong bonding force of active materials to the substrate, which can improve the cycling performance and lower the equivalent series resistance. The Ag/Ni(OH)2 composite electrode exhibits enhanced electrochemical properties with a high specific capacitance of 3.704 F cm−2, coulombic efficiency of 88.3% and long-term cyclic stability.