Enhanced photo/electrocatalytic efficiency of Zn-decorated TiO2 nanostructures for sustainable hydrogen evolution

Monophasic 1, 2.5, and 5 % Zn-decorated TiO2 nanocatalysts have been fabricated by environmentally benign hydrothermal synthesis by avoiding expensive chemicals. As- prepared nanostructures have been investigated utilizing various sophisticated instruments like XRD, scanning and transmission electron microscopy, EDAX, Raman, optoelectronics as well as BET Surface Area studies. 2.5 % Zn- decorated TiO2 was found to have superior photocatalytic performance, exhibiting an H2 formation of 25.55 mmolgcat−1 in 8 hours and average H2 generation of 3.15 mmolgcat−1h−1 at 170 W light intensity. Additionally, electrochemical investigations showed that 5 % and 2.5 % Zn-doped TiO2 had a higher cathodic and anodic current density of 10 mA/cm2 at −0.95, indicating that it has a higher HER catalytic activity, respectively. The synergistic impact of pristine TiO2 and Zn-incorporated TiO2 nanocatalysts is responsible for the increased kinetics of H2 evolution, as it increases the separation and transfer of photo-charged (e-/h+ pair) carriers and decreases redox potential for HER. [Display omitted] •High specific surface areas of pure TiO2 and Zn-doped TiO2 (169.9–247.05 m²/g).•Significant H2 evolution of 25.2 mmol/gcat for 2.5 % Zn-doped TiO2 with 27.89 % AQY.•2.5–5 % Zn-doped TiO2 showed high efficiency for electrocatalytic water splitting.