Exploring the synergistic effect of Ni<sub>x</sub>Sn<sub>2x</sub>S<sub>4x</sub>thiospinel with MWCNTs for enhanced performance in dye-sensitized solar cells, the hydrogen evolution reaction, and supercapacitors
T. Saravanakumar, Selvaraju Thangavelu, K. B. Bhojanaa, M. Ramesh, Alagarsamy Pandikumar, R. Akilan, R. Shankar, Shaik Basha
Abstract
Trifunctional nickel tin sulfide (NixSn2xS4x) with a thiospinel-like structure composited with multiwalled carbon nanotubes (MWCNTs) (M-NixSn2xS4x) was synthesized by a facile method. The unit cell arrangement of the prepared composite was studied by density functional theory, and the theoretical interpretation satisfactorily inferred the presence of a synergistic effect between the thiospinel and MWCNTs. The high metallic conductivity and superior electrocatalytic activity of the M-NixSn2xS4x composite endow it with diverse applications. The composite shows promise as a counter electrode for dye-sensitized solar cells (efficiency of 4.67% for fluorine-doped indium tin oxide compared to 5.23% for platinum); an efficient catalyst for the hydrogen evolution reaction with good cycling stability and a low overpotential of -41 mV at a cathode current density of 10 mA cm2 and a Tafel slope of 43 mV dec-1 on a graphite sheet electrode; and an impressive capacitance material on a graphite sheet electrode alternative to expensive current collectors such as Ni foam, with a specific capacitance value of 1200 F g-1 at a current density of 1 A g-1 and a long life span of 92.6% that is retained for up to 15 000 cycles.