Electrochemical reduction of CO2 to CH4 over transition metal atom embedded antimonene: First-principles study

Research progress of two-dimensional antimonene in energy storage and conversion

Since the first proposal of antimonene in 2015, extensive research attention has been drawn to its application in energy storage and conversion because of its excellent layered structure and fast ion diffusion properties. However, in contrast to the revolutionary expansion of antimonene-based energy devices, reviews on this topic that summarize and further guide the design of 2D antimonene for energy storage and conversion are rare. In this review, the structure, physicochemical properties, and popular synthesis approaches of antimonene are first summarised. Specifically, the rational design and application of antimonene in energy storage and conversion such as electrochemical batteries and supercapacitors, electrocatalytic hydrogen evolution reaction, electrocatalytic oxygen evolution reaction, electrocatalytic carbon dioxide reduction, photocatalytic reduction of organic pollution, photocatalytic reduction of carbon dioxide (CO₂), solar cells and photovoltaic devices are outlined. Finally, opportunities and challenges are presented to further advance the development and application of antimonene in energy conversion and storage.

Sulfur-Decorated Ni-N-C Catalyst for Electrocatalytic CO2 Reduction with Near 100 % CO Selectivity

Developing highly efficient electrocatalysts for electrochemical CO₂ reduction (ECR) to value-added products is important for CO₂ conversion and utilization technologies. In this work, a sulfur-doped Ni-N-C catalyst is fabricated through a facile ion-adsorption and pyrolysis treatment. The resulting Ni-NS-C catalyst exhibits higher activity in ECR to CO than S-free Ni-N-C, yielding a current density of 20.5 mA cm^-2 under -0.80 V versus a reversible hydrogen electrode (vs. RHE) and a maximum CO faradaic efficiency of nearly 100 %. It also displays excellent stability with negligible activity decay after electrocatalysis for 19 h. A combination of experimental investigations and DFT calculations demonstrates that the high activity and selectivity of ECR to CO is due to a synergistic effect of the S and Ni-N_X moieties. This work provides insights for the design and synthesis of nonmetal atom-decorated M-N-C-based ECR electrocatalysts.

Electrocatalytic activity of a β-Sb two-dimensional surface for the hydrogen evolution reaction

Hydrogen energy is considered to be one of the most promising clean energy sources. The development of highly active, low-cost catalysts, and good stability is essential for hydrogen production. Herein, the catalytic activity of a two-dimensional β-Sb surface doped with main-group elements (N, P, As, O, S, Se, and Te) for the hydrogen evolution reaction (HER) was investigated by density functional theory, and the catalytic activity of the β-Sb monolayer can be improved by doping group VIA atoms. The catalytic activity of Se@Sb and O@Sb structures at the doping concentration of 2.78% and the S@Sb structure at the doping concentration of 5.56% may be as good as the Pt(111) surface, while keeping energetically stable. In addition, the catalytic performance could be optimized under biaxial strain. Further analysis suggests that the activity is caused by hole states in the lone pair electrons, which are created by the group VIA atom dopants. And our work also reveals that the density of states at the Fermi level could be an appropriate descriptor of the hydrogenation Gibbs free energy. This work not only proposes a novel non-platinum HER catalyst but also provides physical foundations for further application on antimonene-based catalysts.