High H2 Evolution from Quantum Cu(II) Nanodot-Doped Two-Dimensional Ultrathin TiO2 Nanosheets with Dominant Exposed {001} Facets for Reforming Glycerol with Multiple Electron Transport Pathways

Two-dimensional (2D) ultrathin TiO2 nanosheets doped with quantum Cu(II) nanodots (QCNs) were synthesized through an in situ photodeposition for reforming glycerol. The optimized QCNs dopant exhibited favorable H2 evolution rate of up to 25-fold compared with bare TiO2. The prepared QCNs permeated into the homogeneous {001} facets resulting in discontinuous quantum nanodot doping, which was confirmed by energy-dispersive X-ray (EDX) spectroscopy. Analysis suggests that the suppressed recombination rate of the photoinduced electron–hole pair and the prolonged lifetime are benefits for enhancing photocatalytic performance. A photoinduced interfacial charge-transfer (IFCT) effect introduced by doping QCN was certified by electron spin resonance (ESR) spectroscopy. This offered more photoinduced electrons and holes for redox reaction including H2 production and CO2 and CO yields. Electrochemical characterizations were carried out to reveal that QCN could improve the photocurrent density and shift the conducti...