Synthesis of Host‐Guest Hematite Photoelectrodes for Solar Water Splitting. Issue 7 (3rd June 2019)

• Record Type: Journal Article
• Authors: Francisco, Filipe; Dias, Paula; Ivanou, Dzmitry; Santos, Fátima; Azevedo, João; Mendes, Adélio
• Is Part Of: ChemNanoMat. Volume 5:Issue 7(2019)
• Page Start: 911
• Page End: 920
• Publication Date: 2019-06-03
• Subjects: solar fuels -- solar water splitting -- host-guest approach -- hematite photoelectrodes -- FeNiOOH co-catalyst; Nanochemistry -- Periodicals; Nanostructured materials -- Periodicals; Nanochemistry; Nanostructured materials; Periodicals; 541.2
• DOI: 10.1002/cnma.201900141
• Languages: English
• ISSNs: 2199-692X

Abstract

Abstract: Hematite (α‐Fe2 O3 ) is a promising semiconductor for photoelectrochemical (PEC) water splitting, due to its abundance, low‐cost and excellent stability. However, the efficiency of α‐Fe2 O3 photoelectrodes has been limited by its low hole mobility and fast electron‐hole recombination. Host‐guest architectures have emerged as a suitable design, which involves the use of a nanostructured collector for high solar absorption while maintaining an ultrathin absorber layer for better charge transport. In this study, a thin mesoporous SiO2 host template coated with a conductive thin layer of TiO2 was optimized to support the α‐Fe2 O3 film. The α‐Fe2 O3 thin layer was deposited by spray pyrolysis and then coated with a FeNiOOH co‐catalyst. A photocurrent improvement of ca . 85% over planar α‐Fe2 O3 thin film reference was registered demonstrating the potential of this host‐guest approach. Abstract : A host‐guest architecture was used to improve the performance of hematite photoelectrodes for solar water splitting. For hosting a hematite thin film, a mesoporous SiO2 template was optimized and infiltrated with a conductive TiO2 layer, which displayed better light absorption and faster charge collection. Surface coating with a FeNiOOH co‐catalyst reduced the recombination phenomena and allowed the photocurrent enhancement of ca . 85% compared to the planar hematite thin film.