文摘
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 conduction band (CB) potentials to negative direction. With all the characterizations conducted in this paper, a probable mechanism was proposed to represent the multiple charge-transfer pathways. Here, we provide a new modification strategy for designing QCNs/TiO2 and explore the mechanism involved in 2D ultrathin nanostructures doped with variable-valence metal quantum nanodots. The multiple charge-transfer pathways system applied to photocatalytic H2 production and environmental waste disposition in a facile and green manner may be further employed to synthesize other variable-valence metal doping systems.