Synthetic method, growth mechanism and electrochemical properties of PbSnS2 nanosheets for supercapacitors.

In this work, we have developed a feasible strategy to design ternary metal sulfides of PbSnS2, the mutual Pb2+/Sn2+ substitution in the structure of sulfide elongated c axis of SnS and hindered the change of the cell volume. A facile one-step hydrothermal method was provided to fabricate PbSnS2 nanosheets with excellent supercapacitive properties. Meanwhile, a precipitation-dissolution mechanism is proposed to demonstrate the growth of PbSnS2. The growth progress can be divided into two routes by the precipitative sequence of SnS and PbS. The obtained PbSnS2 will show different morphologies, including flake-like nanosheets, flower-like and cubic-like hierarchical structures, which has large active area and great structural stabilitiy. The as-prepared PbSnS2 has a superior capacitance of 678.8 F·g-1 at 50 mV·s-1 and an extraordinary long-term stability of 95.5 % capacitance retention after 100,000 galvanostatic charge/discharge cycles at 5 A·g-1. Our findings not only enrich the investigations of PbSnS2, but also offer a simple way to design other high performance electrode materials.