Evaluating the role of SnSe on the catalytic activity of co- loaded carbon xerogel for hydrogen evolution reaction

A significant obstacle encountered by electrocatalysts in the hydrogen evolution reaction (HER) is the attainment of high activity, stability, and durability. Tin Selenide (SnSe) has a debated catalytic activity on the HER; some works reported that it is not a good catalyst for HER, while others noted that the pristine SnSe exhibits limited efficiency as a hydrogen evolution reaction catalyst when hydrogen is adsorbed on its basal plane, while the edge sites demonstrate favorable hydrogen adsorption. This study represents the synthesis of a 3D-structure of Co-loaded carbon xerogel (Co-CX) which was further functionalized with SnSe. The Co-CX was synthesized using a straightforward sol-gel approach, which was then functionalized with SnSe by a solvothermal reaction. The prepared composites CX, Co-CX, and SnSe/Co-CX were tested as electrocatalysts for HER in an alkaline medium. The Co-CX exhibited improved HER activity relative to the pristine CX, attributed to the addition of cobalt, which promoted more effective hydrogen adsorption and desorption. The SnSe/Co-CX demonstrated superior HER performance, showcasing a notably reduced onset potential, V_onset of – 0.1 V vs RHE and a lower Tafel slope of 93 mV dec⁻¹, which can be attributed to the synergistic effects of SnSe and Co together with a reduced charge transfer resistance, R_CT of 38 $\Omega$. The SnSe/Co-CX demonstrated excellent stability during 24 h of continuous operation. This investigation emphasizes the potential of SnSe/Co-CX as effective and stable electrocatalysts for HER, providing important perspectives on the development of advanced materials aimed at sustainable hydrogen production.