Cost-effective large-scale synthesis of oxygen-defective ZnO photocatalyst with superior activities under UV and visible light

详细信息    查看全文

• 作者：Jing Wang^a ; ^b ; Ruosong Chen^a ; Yi Xia^a ; ^c ; Guifang Wang^b ; Hongyuan Zhao^b ; Lan Xiang^a ; ^{xianglan@mail.tsinghua.edu.cn} ; Sridhar Komarneni^b ; ^sxk7@psu.edu
• 关键词：D. ZnO ; B. Defects ; C. Optical properties ; Photocatalysis
• 刊名：Ceramics International
• 出版年：2017
• 出版时间：1 February 2017
• 年：2017
• 卷：43
• 期：2
• 页码：1870-1879
• 全文大小：1867 K
• 卷排序：43

文摘

A cost-effective solution method was developed to produce ZnO photocatalyst in large quantity, through the conversion of ε-Zn(OH)2 to ZnO in NaOH solutions. Experimental results indicated that the concentrated NaOH solution (4 mol L−1) promoted the rapid formation of ZnO owing to the enhanced dissolution-precipitation reactions. The large-scale synthesis was also achieved with high-yield and solvent-recyclability. Structural analysis based on X-ray photoelectron spectroscopy, electron spin resonance and photoluminescence revealed that the as-prepared ZnO photocatalyst was rich in oxygen vacancies (VO). The VO-rich ZnO photocatalyst exhibited improved visible-light absorption, higher photocurrent responses and superior activities toward the degradation of rhodamine B under both UV (λ~254 nm) and visible-light illumination (λ>420 nm) compared to commercial ZnO and P25 TiO2 powders, as well as good cycle stability. Based on the results of photoluminescence and active species detection, the VO-enhanced photocatalytic activity was attributed to the generation of VO-isolated level in the band structure. Under UV light, the VO-level could promote charge separation by trapping the photoinduced electrons, while under visible-light, the VO-level improved visible-light absorption and facilitated the charge generation. The presently developed synthesis may potentially benefit the large-scale production and low-cost application of ZnO photocatalyst for solar energy utilization.