title: C-doped ZnO ball-in-ball hollow microspheres for efficient photocatalytic and photoelectrochemical applications.
abstract: ZnO is an important semiconductor and has been widely used in the field of photocatalysis, solar cell and environmental remediation. Herein, we fabricated C-doped ZnO ball-in-ball hollow microspheres (BHMs) by a facile solvothermal treatment of zinc acetate in ethylene glycol-ethanol mixture. The presence of ethylene glycol (EG) leads to the formation of initial single-layered hollow spheres and then a time-dependent evolution transforms them into uniform BHMs with tunable shell thickness and void space. XPS characterizations reveal that C-dopants are introduced into the lattice of ZnO BHMs, with its concentration increasing with solvothermal time and then becoming saturated in 12h. ZEG-12 (ZnO BHMs with 12-h solvothermal treatment), with an optimal hollow structure and C-doping concentration, performs the best optical absorption capability, efficiency of charge separation and transfer, and mass transfer in reaction media, as proved by SEM, TEM, PL, BET and EIS characterizations. When applied as photocatalyst for organic-pollutant degradation and as photoanode material for PEC water splitting, ZEG-12 exhibits respectively ca. 8.9-fold and 10.5-fold higher activity than pristine ZnO nanoparticles.
authors.affiliation: Key Laboratory for Green Chemical Technology of the Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China; Collaborative Innovative Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, China.
authors.forename: Songbo
authors.initials: S
authors.lastname: Wang
authors.affiliation: Key Laboratory for Green Chemical Technology of the Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China; Collaborative Innovative Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, China.
authors.forename: Xiangwen
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Key Laboratory for Green Chemical Technology of the Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China; Collaborative Innovative Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, China.
authors.forename: Shuai
authors.initials: S
authors.lastname: Li
authors.affiliation: Key Laboratory for Green Chemical Technology of the Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China; Collaborative Innovative Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Fang
authors.affiliation: Key Laboratory for Green Chemical Technology of the Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China; Collaborative Innovative Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, China. Electronic address: panlun76@tju.edu.cn.
authors.forename: Lun
authors.initials: L
authors.lastname: Pan
authors.affiliation: Key Laboratory for Green Chemical Technology of the Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China; Collaborative Innovative Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, China.
authors.forename: Ji-Jun
authors.initials: JJ
authors.lastname: Zou
keywords: Ball-in-ball hollow microspheres; C-doping; PEC water splitting; Photocatalysis; Zinc oxide