Designing effective Si/Ag interface via controlled chemical etching for photoelectrochemical CO2 reduction. Issue 44 (3rd August 2018)

• Record Type: Journal Article
• Authors: Hu, Yongpan; Chen, Fengjiao; Ding, Pan; Yang, Hui; Chen, Junmei; Zha, Chenyang; Li, Yanguang
• Is Part Of: Journal of materials chemistry. Volume 6:Issue 44(2018)
• Page Start: 21906
• Page End: 21912
• Publication Date: 2018-08-03
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c8ta05420g
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : Controlled chemical etching of Si wafer by Ag + ions results in the effective Si/Ag interface for photoelectrochemical CO2 reduction to CO. Abstract : Photoelectrochemical reduction of CO2 to value-added chemicals represents a promising approach for artificial photosynthesis, but often suffers from limited selectivity and stability. Improving its performance would require proper design of semiconductor and co-catalyst materials, along with a strategy for effective coupling. Here, we report that controlled chemical etching of Si wafer by Ag + ions yields effective semiconductor/co-catalyst interface for photoelectrochemical CO2 reduction. Resultant photocathodes exhibit large photocurrent density (∼10 mA cm −2 under 0.5 sun), great CO faradaic efficiency (90% at −0.5 V versus reversible hydrogen electrode), and impressive operational stability (little activity or selectivity loss within 8 h). Further enhancement (by ∼20%) of photocurrent density is achieved by combining photolithography patterning with chemical etching. Our study applies long-known chemistry as an unexpected solution and may provide a new strategy for high-performance photoelectrochemical CO2 reduction.