Direct growth of three-dimensional nanoflower-like structures from flat metal surfaces

Obtaining materials from local sources: surface modification engineering enabled substrates for water splitting

The preparation of an efficient electrode is the key to achieving efficient overall water-splitting for H2 production. Substrate surface modification engineering (SSME) provides a feasible method for preparing self-supported electrodes with high active site utilization, fast mass transport, and a simple fabrication process. This review summarizes and discusses the recent advances in preparing transition-metal-based HER/OER electrocatalysts via SSME. We first highlight the description and advantages of SSME, followed by the detailed introduction of electrocatalysts prepared via the SSME, such as hydroxides, oxyhydroxides, chalcogenides, phosphides, and borides. Finally, we provide the challenges and perspectives. We hope that this review will provide inspiration for researchers and stimulate the development of water splitting technology.

Nanostructured cobalt/copper catalysts for efficient electrochemical carbon dioxide reduction

The search for an efficient and stable catalyst for the electrochemical reduction of CO2 to value-added chemicals is especially critical for lowering the atmospheric CO2 concentration. In this study, self-supported cobalt/copper nanostructured catalysts were designed, where the influences of the elemental composition and acid-etching on their efficiency towards the CO2 reduction reaction were studied. The developed Co/Cu catalysts showed superb catalytic activity with a low onset potential at -0.2 V vs. RHE. Gas and liquid product analysis revealed that formate and CO were the main products. It was observed that lower reductive potentials were favourable for formate production, while higher reductive potentials were more favourable for CO formation. In situ electrochemical FTIR studies were further conducted to gain insight into the CO2 reduction mechanism. The novel synthetic procedure reported in this study leads to promising electrocatalysts with high efficiencies for the conversion of CO2 into valuable products.

Oxygen vacancy modulated Fe-doped Co3O4 hollow nanosheet arrays for efficient oxygen evolution reaction

Herein, Fe-doped Co3O4 hollow nanosheet arrays with rich oxygen vacancies (Vo-Fe-Co3O4) are constructed using a facile strategy. Benefiting from the compositional and structural superiorities, Vo-Fe-Co3O4 exhibits a remarkable OER overpotential of 231 mV at 10 mA cm-2 and a Tafel slope of 57.45 mV dec-1 in an alkaline medium.

Recent Advances in Synthesis and Application of Metal Oxide Nanostructures in Chemical Sensors and Biosensors

Nanostructured materials formed from metal oxides offer a number of advantages, such as large surface area, improved mechanical and other physical properties, as well as adjustable electronic properties that are important in the development and application of chemical sensors and biosensor design. Nanostructures are classified using the dimensions of the nanostructure itself and their components. In this review, various types of nanostructures classified as 0D, 1D, 2D, and 3D that were successfully applied in chemical sensors and biosensors, and formed from metal oxides using different synthesis methods, are discussed. In particular, significant attention is paid to detailed analysis and future prospects of the synthesis methods of metal oxide nanostructures and their integration in chemical sensors and biosensor design.