Study on the local electric field effect of electron transfer in straw-derived carbon microsphere-WO3 composite materials: Photocatalytic hydrogen production performance and mechanism under solar light

• WO 3 -corn straw carbon microspheres are successfully prepared. • WO 3 -corn straw carbon microspheres show sun light catalytic performance. • The possible mechanism of sun light catalytic is analyzed. Solar photocatalytic hydrogen production is an important technology for green hydrogen energy production. However, due to the limitation of the light absorption band of photocatalysts, the most commonly used catalysts are difficult to achieve efficient and stable photocatalysis under sunlight. Herein, a carbon microsphere-WO 3 composite photocatalytic material was prepared by hydrothermal synthesis, which accelerated the directional transfer of photogenerated electrons. There is a strong local electric field effect in the carbon microsphere-WO 3 composite photocatalytic material, promoting the directional transfer of electrons. Photogenerated carriers rapidly migrate from WO 3 to the active sites on the surface of carbon microspheres, improving the kinetics of the photocatalytic H + reduction reaction and accelerating the efficiency of solar photocatalytic hydrogen production. When the doping concentration of carbon microspheres is 30%, the photocatalytic hydrogen production rate of the composite material reaches 520 μmol·h -1 ·g -1 , which is 32.5 times that of pure WO 3 . The carbon microsphere-WO 3 composite photocatalytic material has superior photo-stability and recyclability. The experimental results reveal the reaction mechanism of the efficient catalysis of the composite material. This study opens up new prospects for the practical application of photocatalysts.