A three-dimensional porous CoSnS@CNT nanoarchitecture as a highly efficient bifunctional catalyst for boosted OER performance and photocatalytic degradation.

It is urgent and significant to develop competent, inexpensive transition metal-based catalysts with multifunctional catalytic properties for wide applications. To meet this requirement, herein, for the first time, we present a novel bifunctional CoSnS@CNT hybrid via a simple one-pot surfactant-free hydrothermal method. The CoSnS@CNT hybrid has a unique three-dimensional (3D) porous nanoarchitecture, which is constructed by ultrathin CoSnS homogenously and compactly anchored on a highly conductive CNT skeleton. The porous nanoarchitecture of CoSnS@CNT provides abundant catalytic sites and facilitates ion diffusion, and the CNT skeleton accelerates electron transfer. Benefitting from these merits, the CoSnS@CNT hybrid acted as a bifunctional catalyst with boosted electrocatalytic and photocatalytic performance, where it delivered a tremendous oxygen evolution reaction (OER) performance with a low overpotential of 330 mV at a current density of 10 mA cm and excellent outstanding stability. Moreover, it showed 91.72% photocatalytic degradation for Rhodamine B dye, which is 2-times higher than that of bare CoSnS. This study presents a systematic approach to judiciously design nanostructures and simply synthesize non-noble metal-based bifunctional catalysts with boosted electrocatalytic and photocatalytic activities.