Surface engineering has been found to be an efficient strategy to boost the catalytic performance of noble-metal-based nanocatalysts. In this work, a small amount of P was doped to the surface of PtNi concave cube (P-PtNi CNC). Interestingly, the P-PtNi CNC nanocatalyst shows an enhanced methanol oxidation reaction (MOR) performance with achieving 8.19 times of specific activity than that of comercial Pt/C. The electrochemical in situ Fourier transform infrared spectroscopy (FTIR) results reveal that the surface P doping promotes the adsorption energy of OH, enhancing the resistance against CO poisoning. Therefore, the intermediate adsorbed CO (CO_ads) reacted with adsorbed OH (OH_ads) through the Langmuir—Hinshelwood (LH) mechanism to generate CO₂ and release surface active sites for further adsorption. This work provides a promising strategy via the incorporation of non-metallic elements into the PtNi alloys bounded with high-index facets (HIFs) as efficient fuel cell catalysts.

Lithium-ion capacitors (LICs) are attracting increasing attention because of their potential to bridge the electrochemical performance gap between batteries and supercapacitors. However, the commercial application of current LICs is still impeded by their inferior energy density, which is mainly due to the low capacity of the cathode. Therefore, tremendous efforts have been made in developing novel cathode materials with high capacity and excellent rate capability. Graphene-based nanomaterials have been recognized as one of the most promising cathodes for LICs due to their unique properties, and exciting progress has been achieved. Herein, in this review, the recent advances of graphene-based cathode materials for LICs are systematically summarized. Especially, the synthesis method, structure characterization and electrochemical performance of various graphene-based cathodes are comprehensively discussed and compared. Furthermore, their merits and limitations are also emphasized. Finally, a summary and outlook are presented to highlight some challenges of graphene-based cathode materials in the future applications of LICs.