Photocatalytic hydrogen production via water splitting using sunlight as the energy resource is of worldwide interest, due to its possibility to solve the most two serious problems of energy crisis and environmental pollution. Hence, we are dedicated in the researching and studying of the technology to produce hydrogen in a cost-effective and low –GHG (greenhouse gas) manner. In our work, great efforts have been made to enhance the photocatalytic activity for hydrogen evolution over graphitic carbon nitride via heterojunction construction and morphology design based on strengthened separation and transfer of photo-generated charges. Meanwhile, we are also focusing on the synthesis and optimization of copper plasmonic nanostructures for efficient solar hydrogen conversion, which presents a promising prospect and research value.
Molecular catalysis system containing earth-abundant elements (e.g., Fe, Co, Ni) for has attracting increasing attentions due to its low cost, high atom utilization and versatile designability. We are focusing on the design of molecular artificial photosynthesis systems for photo(electro)chemical or electrochemical renewable energy conversion. In our work, we have fabricated several Co or Ni-based artificial photosynthesis systems for efficient solar water splitting, which exhibited impressive photo(electro)chemical performance under visible light irradiation from fully aqueous solutions.
Since Fukushima and Honda first reported TiO2 based photoelectrochemical (PEC) water splitting cell in 1972, PEC water splitting has aroused widespread attention due to its cleanness and low cost. It can capture and store the solar energy in the form of stable chemical energy. Actually, the key to achieve efficient PEC water splitting is searching and developing suitable semiconductor materials used as photoelectrodes. In our group, we mainly focus on the following semiconductor photoelectrodes: Fe2O3, TiO2, ZnO, Cu2O and Si. We have successfully synthesized the above semiconductors with specific morphology structure and size. Besides, a series of modification ways were used to enhance their PEC performance, such as nanostructure, element doping, hetrostructure design and etc. We are committed to provide a theoretical basis for regulating the dynamics and thermodynamics of photoelectrodes and achieving efficient PEC solar water splitting.
The water-splitting reaction can be viewed as a combination of two half reactions:
hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). In addition,
oxygen reduction reaction (ORR) is the backward reaction of OER, which is significant in metal-air battery.
Various materials can be used for obtaining higher reaction rate and better stability, such as transition metal materials (e.g., Fe, Co, Ni)
and their oxides, hydroxides, carbides, nitrides and sulfides, carbon-based catalysts (e.g., graphene, carbon nanotube)
and the composites. We are using several methods for synthesizing nanoscale catalysts and exploring deeply for better electrochemical performance.
CO2 reduction is currently attractive. Recent studies show that oxides and hydroxides of some transition metals (Cu, Fe, Co, Ni, Mn etc.) and some metal-free functional materials (C3N4, graphite, grapheme etc.) are of great potential in electrocatalytic CO2 reduction. Nevertheless, compared to Au and Ag, these new materials are still restricted by their low activity and stability in practical applications. Further, it is crucial to clarify the reaction mechanism for in-depth understanding and guidance of material synthesis and experiment design. Higher transfer efficiency, better selectivity, longer duration, lower cost and toxicity are worthwhile goals for industrial application.