Graphene quantum dots to enhance the photocatalytic hydrogen evolution efficiency of anatase TiO2 with exposed {001} facet.
Hydrogen evolution through photocatalysis is promising with respect to the environmental problems and challenges of energy shortage that we encounter today. In this paper, we have combined graphene quantum dots (GQDs) and {001} faceted anatase TiO2 (with an exposed percentage of 65-75%) together for effective photocatalytic hydrogen evolution. A series of characterizations including X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy and UV-visible absorption spectroscopy have been carried out to study the structure of the as-prepared GQDs/{001}TiO2 composite. It turns out that GQDs could be effectively decorated on {001}TiO2 sheet without changing its intrinsic structure. With an optimum loading amount of GQDs (0.5 wt% to {001}TiO2), GQDs/{001}TiO2 exhibits a hydrogen evolution efficiency 8 times higher than that of bare {001}TiO2, which is a significantly more obvious improvement than many other photocatalytic systems relevant to GQDs and TiO2 hybrids. In addition, GQDs/{001}TiO2 could stand long-term photocatalytic experiments. Photocurrent tests show that such an improvement of the photocatalytic efficiency over GQDs/{001}TiO2 may originate from a higher charge separation efficiency. The present study could offer reference for the construction of photocatalytic hydrogen evolution systems with low cost and long term stability.
School of Materials Science and Engineering, Southwest Petroleum University, Chengdu 610500, China. yzhou@swpu.edu.cn.
Shan
S
Yu
School of Materials Science and Engineering, Southwest Petroleum University, Chengdu 610500, China. yzhou@swpu.edu.cn.
Yun-Qian
YQ
Zhong
School of Materials Science and Engineering, Southwest Petroleum University, Chengdu 610500, China. yzhou@swpu.edu.cn.
Bao-Quan
BQ
Yu
School of Materials Science and Engineering, Southwest Petroleum University, Chengdu 610500, China. yzhou@swpu.edu.cn.
Shi-Yi
SY
Cai
Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, the Chinese Academy of Sciences, Beijing 100190, P. R. China.
Li-Zhu
LZ
Wu
School of Materials Science and Engineering, Southwest Petroleum University, Chengdu 610500, China. yzhou@swpu.edu.cn and State Key Laboratory of Oil and Gas Reservoir and Exploitation, Southwest Petroleum University, Chengdu 610500, China.
Ying
Y
Zhou