Haixia Liu

A mechanochemical ball-milling and calcination method constructed NiO/mica with a layered structure and excellent OER activity, achieving 10 mA cm⁻² at 270 mV overpotential.

With the continuous growth of global energy demand and the increasingly severe environmental issues, the extensive utilization of traditional fossil fuels has led to serious energy crises and environmental pollution problems. In this study, a hydrothermal method was employed, and by adding ethanolamine and controlling different temperatures, pink zinc sulfide with zinc vacancies was synthesized. UV-Vis DRS analysis indicated that the sample exhibited significant visible light absorption characteristics within the wavelength range of 500–550 nm. The presence of zinc vacancies was confirmed through XPS. Due to the existence of zinc vacancies, the sample demonstrated excellent photocatalytic hydrogen evolution activity without the need for co-catalysts, with the optimal sample achieving a hydrogen evolution rate of 7631.70 μmol h⁻¹ g⁻¹. Zinc vacancies can provide additional active sites, enhance catalytic efficiency, and promote the separation of photogenerated electrons and holes. Furthermore, the introduction of vacancies effectively reduces the bandgap of the material, significantly broadening its visible light absorption range. This work provides a new approach for enhancing hydrogen evolution in pure ZnS and offers novel strategies for the further design of ZnS-related photocatalysts.

The construction of heterojunctions can effectively inhibit the rapid recombination of photogenerated electrons and holes in photocatalysts and offers great potential for pollutant degradation. In this study, a Z-scheme heterojunction g-C₃N₄/WO₃ photocatalyst was synthesized using a combination of hydrothermal and calcination methods. The photocatalytic degradation performance was tested under visible light; the degradation efficiency of Rh B reached 97.9% within 15 min and that of TC-HCl reached 93.3% within 180 min. The excellent photocatalytic performance of g-C₃N₄/WO₃ composites can be attributed to the improved absorption of visible light, the increase in surface area, and the effective separation of photogenerated electron–hole pairs. In addition, after four cycles of experiments, the photocatalytic performance of g-C₃N₄/WO₃ did not decrease obviously, remaining at 97.8%, which proved that the g-C₃N₄/WO₃ heterojunction had high stability and reusability. The active radical capture experiment confirmed that h⁺ and ·O₂⁻ played a leading role in the photocatalytic degradation. The Z-scheme heterojunction g-C₃N₄/WO₃ designed and synthesized in this study is expected to become an efficient photocatalyst suitable for environmental pollution control.

The development of low-cost, highly active, and stable electrocatalytic water-splitting catalysts is crucial to solving the current energy crisis and environmental pollution. Herein, a simple two-step conversion strategy is proposed to successfully prepare NiFeS nanosheet structure catalyst through the “immersion-sulfurization” strategy. The self-supported electrode can be prepared in large quantities due to its simple preparation process. As an active substance, NiFeS can grow directly on the NiFe foam substrate, avoiding the use of adhesives or conductive agents, and directly used as electrodes. The as-obtained NiFeS/NFF-300 displays efficient catalytic activity in electrocatalytic water splitting. The overpotential required for OER of the NiFeS/NFF-300 electrode at a current density of 10 mA cm⁻² is 230 mV. The electrode underwent a stability test at 10 mA cm⁻² for 24 h, and the overpotential remained essentially unchanged, demonstrating excellent stability. Moreover, NiFeS/NFF-300 exhibits considerable HER performances compared with NiFeC₂O₄/NFF and NiFe foam. The unique nanosheet structure and the presence of Ni^δ+ and Ni²⁺ formed by NiFe foam substrate on the NiFeS surface are responsible for its excellent electrocatalytic activity.

Compared to traditional actuators (such as piezoelectric ceramics), metal actuators possess the advantages of a low energy consumption, large strain amplitude, and high strain energy density. However, most of the existing metal actuators with an excellent comprehensive performance are composed of precious metals, which are limited by high costs and have almost no possibility for large-scale production in the future. This study focuses on non-precious metal materials and exploits a one-step chemical dealloying method to prepare bulk nanoporous (NP) CoCuAl actuators (NP-CCA) from Al₇₀Co₂₀Cu₁₀ alloy. The microstructure and actuation properties of the NP-CCA were analyzed in detail. The dense continuous nanoscale pores provide an excellent network connectivity for a large strain response, enabling the NP-CCA to achieve a strain amplitude of up to 1.19% (more than eight and two times that of NP-Pt and NP-Ag, respectively), comparable to precious metal actuators. In addition, the NP-CCA possesses a high strain energy density, which is prominent in many precious metal actuation materials (such as NP-Au, NP-Ag, and NP-Pt).