Platinum nanoclusters by atomic layer deposition on three-dimensional TiO2 nanotube array for efficient hydrogen evolution

Electrode design plays an important role in improving hydrogen evolution reaction (HER), and the self-supporting electrode with three-dimensional (3D) porous structure is widely adopted in the electrocatalytic hydrogen evolution. To better the performance of Pt catalyst for hydrogen evolution, a layer of TiO2 nanotube arrays (TiO2 NTs) fabricated on titanium mesh (3D-Ti) or plate Ti (P-Ti) substrate, respectively, has been selected as support materials to load Pt nanocluster (Ptx/TiO2 NTs@3D-Ti and Ptx/TiO2 NTs@P-Ti) via an atomic layer deposition method. It has been revealed that one chemical bond of Ti-O-Pt had been formed between Pt nanocluster and TiO2 nanotube. The theoretical calculations confirm that Ti-O-Pt bond can not only improve the stability of Pt nanocluster but also improve its capability for hydrogen evolution. In addition, the 3D-Ti substrate with open structure can further better Pt nanoclusters’ performance on hydrogen evolution. The obtained Ptx/TiO2 NTs@3D-Ti electrode exhibits an overpotential of 53 mV in 0.5 M H2SO4 at −10 mA cm−2, and its mass activity has been improved by a factor of 18 compared with Ptx/TiO2 NTs@P-Ti.