Trace amounts of palladium-doped hollow TiO2 nanosphere as highly efficient electrocatalyst for hydrogen evolution reaction

Hollow titanium dioxide (TiO2–H) sphere and Pd@TiO2–H core-shell were successfully synthesized through hydrothermal method, and their electrocatalytic properties for hydrogen evolution reaction (HER) were evaluated The 0.05 wt%Pd@TiO2–H achieved the lowest overpotential of 0.43V at 10 mA cm−2 with a Tafer slope of 63 mV dec−1, which were both apparently outperforming than that of the commercial TiO2 (0.92 V, 636 mV dec−1). Electrochemical stability was also confirmed by a negligible attenuation for polarization curves before and after 5000 cycles. The attractive performance can be attributed to the special hollow structural and Pd doping effect resulting in the increased amount of active sites. This study provides a special material to develop lower cost, more stable and efficient titanium oxide based electrocatalysts for HER.