Zeng Peng, Ji Xiaoyuan, Su Zhiguo, Zhang Songping
State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences Beijing 100190 P. R. China
University of Chinese Academy of Sciences Beijing 100049 P. R. China.
RSC Adv. 2018 Jun 5;8(37):20557-20567. doi: 10.1039/c8ra02807a.
A heterogeneous WS/g-CN composite photocatalyst was prepared by a facile ultrasound-assisted hydrothermal method. The WS/g-CN composite was used for photocatalytic regeneration of NAD to NADH, which were coupled with dehydrogenases for sustainable bioconversion of CO to methanol under visible light irradiation. Compared with pristine g-CN and the physical mixture of WS and g-CN, the fabricated WS/g-CN composite catalyst with 5 wt% of WS showed the highest activity for methanol synthesis. The methanol productivity reached 372.1 μmol h g , which is approximately 7.5 times higher than that obtained using pure g-CN. For further application demonstration, the activity of the WS/g-CN composite catalyst toward photodegradation of Rhodamine B (RhB) was evaluated. RhB removal ratio approaching 100% was achieved in 1 hour by using the WS/g-CN composite catalyst with 5 wt% of WS, at an apparent degradation rate approximately 2.6 times higher than that of pure g-CN. Based on detailed investigations on physiochemical properties of the photocatalysts, the significantly enhanced reaction efficiency of the WS/g-CN composite was considered to be mainly benefiting from the formation of a heterojunction interface between WS and g-CN. Upon visible-light irradiation, the photo-induced electrons can transfer from the conduction band of g-CN to WS, thus recombination of electrons and holes was decreased and the photo-harvesting efficiency was enhanced.
采用简便的超声辅助水热法制备了一种异质结构的WS/g-CN复合光催化剂。该WS/g-CN复合材料用于将NAD光催化再生为NADH，其与脱氢酶偶联，在可见光照射下将CO可持续生物转化为甲醇。与原始g-CN以及WS和g-CN的物理混合物相比，含5 wt% WS的WS/g-CN复合催化剂对甲醇合成表现出最高活性。甲醇生产率达到372.1 μmol h g，约为使用纯g-CN时的7.5倍。为进一步进行应用示范，评估了WS/g-CN复合催化剂对罗丹明B（RhB）的光降解活性。使用含5 wt% WS的WS/g-CN复合催化剂，在1小时内实现了近100%的RhB去除率，表观降解速率约为纯g-CN的2.6倍。基于对光催化剂理化性质的详细研究，认为WS/g-CN复合材料反应效率的显著提高主要得益于WS和g-CN之间形成的异质结界面。在可见光照射下，光生电子可从g-CN的导带转移至WS，从而减少了电子与空穴的复合，提高了光捕获效率。
