Investigation of palladium-doped 2D g-C3N5 materials for enhanced electrocatalytic activity towards hydrogen evolution reaction

Abstract

Hydrogen is widely recognized as an extremely environmentally friendly energy source due to its unique characteristics, notably its high energy density and complete absence of carbon emissions. The electrocatalytic technique is the most efficient for hydrogen production among various techniques. Designing an electrocatalyst that is highly electrochemically efficient, catalytically active, stable, cost-effective, and environmentally durable, especially in harsh conditions (highly acidic and basic), is still challenging. Herein, the new set of compositions of Pd-doped g-C3N5 was successfully synthesized by a simple carbonization method using a mixture of 3-amino-1,2,4-triazole (3AT) and PdCl2. Among these materials, nanosheets synthesized g-C3N5/Pd-1 % with the optimized ratio demonstrate the most impressive electrocatalytic performance for the hydrogen evolution reaction (HER). This material exhibits a very low onset overpotential of approximately -10 mV vs. RHE, the smallest Tafel slope value of 47.6 mV dec‑1, and achieves a current density of 10 mV/cm−2 at an overpotential of 69 mV vs. RHE. The catalytic materials also offer very good stability and durability for electrocatalytic HER activity. The upgraded catalytic activity towards HER of g-C3N5/Pd-1 % results from the improved and easy charge transfer and optimized synergism between Pd and g-C3N5. Hence, the synthesized g-C3N5/Pd-1 % materials could potentially serve as a substitute for Pt-based electrocatalysts in practical hydrogen production for the hydrogen evolution reaction (HER).