Controlling the formation of self-assembled Cu–Sn sulfide with a hoya-like structure for its electrochemical performance

Abstract

Cu–Sn binary sulfide is a promising candidate for an electrode material due to its superior properties, and it has been extensively reported in solar cells and Li-ion batteries. However, there are only a few pieces of work about its use in either supercapacitors or electrocatalysts. In this work, self-assembled binary sulfides with different morphologies in terms of 1D Cu–Sn–S micron-tubes (MTs-CTS), 1D Cu–Sn–S submicron-tubes (SMTs-CTS) and 3D Cu–Sn–S hoya-like micron-spheres (MPs-CTS) with honeycomb pores were successfully fabricated via a facile gelation–solvothermal–annealing three-step method. The results show that MPs-CTS achieve better electrochemical performance compared with MTs or SMTs. The optimized MPs-CTS exhibit a higher capacitance value (1134.2 F g⁻¹ at 1 A g⁻¹), better rate capability, and longer-term cycle stability (94.2% retention after 2000 cycles at 5 A g⁻¹). Moreover, the MPs-CTS also display excellent hydrogen evolution reaction (HER) performance at a current density of 10 mA cm⁻² with the lowest overpotential of 302 mV and a small Tafel slope of 78 mV dec⁻¹. This work provides an effective route for the design and preparation of a 3D hoya-like structure with multiple functions, such as energy storage and electrocatalysis.