Hongmei Zhao,Tingting Zhang,Dongyu Shan,Ying Zhu,Ge Gao,Ye Liu,Jing Liu,Meiying Liu,Wansheng You
An intervening barrier for photocatalytic water decomposition and pollutant degradation is the frustratingly quick recombination of e − - h + pairs. Delicate design of heterojunction photocatalysts by coupling the semiconductors at nanoscale with well-matched geometrical and electronic alignments is an effective strategy to ameliorate the charge separation. Here a facile and environment-friendly l -cysteine-assisted hydrothermal process under weakly alkaline conditions is demonstrated for the first time to fabricate ZnIn 2 S 4 /In(OH) 3 hollow microspheres with intimate contact, which are verified by XRD, SEM, (HR)TEM, XPS , N 2 adsorption-desorption, UV–Vis DRS and photoluminescence spectra. ZnIn 2 S 4 /In(OH) 3 heterostructure (L-cys/Zn 2+ = 4, molar ratio) with a band-gap of 2.50 eV, demonstrates the best photocatalytic performance for water reduction and MB degradation under visible light, outperforming its counterparts (In(OH) 3 and ZnIn 2 S 4 ). The excellent activity of ZnIn 2 S 4 /In(OH) 3 heterostructure arises from the intercrossed band-edge positions as well as the unique hollow structure with large surface area and wide pore-size distribution, which are beneficial for the efficient charge migration from bulk to surface as well as at the interface between ZnIn 2 S 4 and In(OH) 3 . This work provides an efficient and eco-friendly strategy for one-pot synthesis of heterostructured composites with intimate contact for photocatalytic application.
During the photocatalytic production of hydrogen gas, close interface with a catalyst is very important. We designed a noble-metal-free photocatalytic system that is spatially separated to produce hydrogen by high frequency visible light. We used a new type of a catalyst consisting of hollow core-shell CdS@TiO 2 /Ni 2 P structures prepared using sacrificial template method. Photocatalytic decomposition of water was tested using this catalyst. Hydrogen production yield using 420 nm light was 14.80 mmol/g after 2.5 h and using Xe lamp with AM1.5G filter was 34.78 mmol/g after 2.5 h. Hollow core shell CdS@TiO 2 /Ni 2 P particles were more stable than hollow core shell CdS@TiO 2 /Pt structures because TiO 2 protected CdS from photo-corrosion. Combination of CdS and Ni 2 P increased absorption range of TiO 2 at 720 nm. Holes and electrons produced during the photo-reaction can migrate to the CdS on the inside and to the Ni 2 P on the outside of the TiO 2 protective coating. Such design exposes more surface, thus, increases hydrogen production.
危险品化学品经营许可证（带存储）