Bifunctional intermetallic PdZn nanoparticle-loaded deficient TiO2 nanosheet electrocatalyst for electrochemical water splitting

Abstract

Catalysts for electrochemical water splitting are receiving remarkable consideration, and raw materials and methods for preparing catalysts are important. Through an impregnation method using low-temperature heating, a concise technique for the preparation of layered TiO_2−x NSs incorporating PdZn nanoparticles (NPs) has been established in this work. With an overpotential of 64 mV at 10 mA cm⁻² and a low Tafel slope of 68 mV dec⁻¹ in 1 M KOH at ambient temperature, the synthesized PdZn NP-decorated TiO_2−x NSs (PdZn/TiO_2−x NSs) showed better catalytic activity for the hydrogen evolution reaction (HER). The same was observed for the oxygen evolution reaction (OER); the PdZn/TiO_2−x NSs showed satisfactory electrocatalytic performance, delivering a current density of 10 mA cm⁻² at an overpotential of 0.46 V and a Tafel slope of 115 mV dec⁻¹. Furthermore, the PdZn/TiO_2−x NS electrocatalyst also exhibited high stability in a constant voltage electrochemical water splitting operation for 35 h. The synergistic impact of TiO_2−x NSs and PdZn, higher conductivity, and large electrochemical active surface area are all factors contributing to the electrocatalyst's improved HER and OER performance. The highly active electrocatalyst demonstrated in this work, as well as its simple preparation method, will encourage the development of other transition metal catalysts supported on carbon-free nanostructured supports for future large-scale applications in electrochemical water splitting.