MOF derived M/Sn/N (M= Mg, Mn) based carbon nanospheres as highly efficient multicomponent electrocatalysts towards hydrogen evolution and photovoltaics

Abstract

Constructing multicomponent electrocatalysts towards efficient energy conversion is widely adopted strategy, in this regard, high performance metal/nonmetal codoped carbon electrode materials have attained great consideration. Still, the electroacatalytic susceptibility, abundant intrinsic active sites, and stable electrochemical performance in different electrolytes are considered as underline challenges, which can be addressed by rational structural modifications to build a hybrid electroactive material. In this work, unique Sn based multicomponent carbon nanospheres are firstly developed as highly efficient bi-functional electrocatalysts in solar cells and hydrogen evolution. The designed electrocatalysts feature the combined effect of dispersed bimetal active sites and sufficient nitrogen components within spherical carbon framework, which readily enhanced the charge transfer rate via multiple channels, boosting the triiodide reduction reaction (IRR) and hydrogen evolution reaction (HER). As a result, solar cell with Mn/Sn-NC based counter electrodes (CEs) exhibited an excellent power conversion efficiency (PCE) of 8.39 %, outperforming Pt (7.67 %). Moreover, superior HER kinetics are also demonstrated by Mn/Sn-NC with a small overpotential of 127.8 mV at 10 mA cm⁻² and tafel slope of 77 mV dec⁻¹. The rational design of the carbon nanospheres with MnSn₂ bimetal nanoparticles and N doping promotes a high electrochemically active surface area, low charge-transfer resistance, excellent electrochemical stability, and superior electrocatalytic activity, providing a promising route to construct highly efficient materials towards multiple energy conversion applications.