One-Step Hydrothermal Synthesis of a Cu Single Atom-TiO2 Catalyst for Efficient Photocatalytic H2 Evolution

XPS: Surface elemental composition was determined by X-ray photoelectron spectroscopy (XPS, AXIS Ultra DLD);AC-HAADF-STEM: The surface morphology was characterized using aberration-corrected high-angle annular dark-field scanning transmission electron microscopy (AC-HAADF-STEM, JEOL arm 200F);XRD: The crystalline structure of the prepared samples was analyzed using X-ray diffraction (XRD, D8 Advance) with Cu Kα radiation;UV: Ultraviolet-visible diffuse reflectance spectra (UV-vis DRS) were recorded with a UV-3600 Plus spectrophotometer, using barium sulfate as the reference;I-t and EIS:,the catalytic activity was investigated through photoelectrochemical analysis, I-t and EIS were conducted using a CHI 650e potentiostat (Shanghai Chenhua).