研究主题：纳米催化与能源转化 (Nanocatalysis and Energy conversion)
Our research goal is designing and synthesizing new nanostructures based on inorganic synthesis chemistry, exploring their potential applications in the field of energy storage and transformation (photocatalytic reduction of CO2, water splitting, electrolysis of water, fuel cell, metal-air batteries, supercapacitors, etc), demonstrating the relationships between composition, morphology and structure defects of nanostructures and performances, and developing advanced optical/electrical catalytic and supercapacitor materials. After 12 years of development and accumulation, our group has formed the following three stable research directions.
Photocatalytic technologies use semiconductors to convert solar energy into chemical energy, such as photocatalytic water splitting to hydrogen and photoreduction of CO2 to CH4, which can not only generate clean fuels and alleviate the increasing energy crisis, but also reduce atmospheric CO2 and slow down the greenhouse effect. Single-component semiconductors show low photocatalytic activity due to fixed energy band structure, high recombination rate of photogenerated electron-hole pairs, and sluggish surface reactions. Precious metal-contained photocatalysts generally have better photocatalytic activity. However, high cost and the need of sacrifice agents are the factors that significantly limit their commercialization process. In order to develop efficient and cost-effective photocatalysts, various strategies such as defect engineering, surface engineering and heterojunction engineering have been proposed for semiconductors without precious metals to improve their photoactivity. At present, the multi-strategy integrated photocatalysts have shown comparable or even better performances than precious metals-containing catalysts, and its design and assembly have become the current research hotspot.
The development of green nanotechnologies such as fuel cells, metal-air cells, and water decomposition systems has emerged as a promising way to address the growing energy needs and environmental problems of modern society. In the above systems, hydrogen evolution (HER), oxygen evolution (OER) and oxygen reduction reactions are important half reactions, which govern the energy storage and conversion processes of devices. In order to facilitate these reactions, it is urgent to develop stable electrode materials with excellent electrochemical activity. Among them, precious metal catalysts possess excellent electrocatalytic performance. However, high cost, scarcity, and poor stability of traditional precious metals significantly hinder large-scale commercial applications. Therefore, the development of cost-effective nano-catalysts with multi-/bi-functions is a research hotspot in the field of electrocatalysis.
Supercapacitors have a wide application prospect in mobile electronics and regenerative braking systems due to the following merits: high power density, fast charge and discharge, long cycle life and high safety. However, the relatively low energy density greatly limits their applications in the future. In order to improve the energy density of supercapacitors without sacrificing the power density, it is a good choice to build hybrid supercapacitors. Therefore, the key to assemble high-performance hybrid supercapacitors is to design and develop new and efficient electrode materials.