Regulation of hydrogen evolution performance of titanium oxide-carbon composites at high current density with a Ti-O hybrid orbital

Rational design and controllable synthesis of practical electrodes with high stability and activity at high current density for a hydrogen evolution reaction (HER) are critical for renewable and sustainable energy conversion. However, high-performance TiO2-based electrocatalysts for HER are quite limited, and the catalytic active centers still remain elusive. Herein, a simple strategy is demonstrated for the synthesis of TiO2-carbon composite (TiO2/C) with high HER performance and stability. The remarkable HER performance of TiO2/C can be ascribed to the doping of carbon atoms, which leads to stronger hybridization of Ti 3d and O 2p orbitals, thus substantially improving the electrocatalytic efficiency. This study elucidates that the hydrogen evolution activity of oxide electrocatalysts can be largely improved by regulating their electronic structures by doping carbon atoms and also provides an effective strategy for designing heterostructured electrocatalysts with high catalytic activity and stability at high current density for HER.