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Enhancing Solar‐Driven Water Splitting with Surface‐Engineered Nanostructures
Author(s) -
Shen Shaohua,
Lindley Sarah A.,
Dong ChungLi,
Chen Eefei,
Lu YingRui,
Zhou Jigang,
Hu Yongfeng,
Wheeler Damon A.,
Guo Penghui,
Zhang Jin Z.,
Kliger David S.,
Mao Samuel S.
Publication year - 2019
Publication title -
solar rrl
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.544
H-Index - 37
ISSN - 2367-198X
DOI - 10.1002/solr.201800285
Subject(s) - overlayer , nanorod , water splitting , materials science , nanostructure , hematite , charge carrier , nanotechnology , chemical engineering , photocatalysis , optoelectronics , chemistry , catalysis , biochemistry , engineering , metallurgy
Functional nanoscale interfaces that promote the transport of photoexcited charge carriers are fundamental to efficient hydrogen production during photoelectrochemical (PEC) splitting of water. Here, the realization of a functional one‐dimensional nanostructure achieved through surface engineering of hematite (α‐Fe 2 O 3 ) nanorods with a TiO 2 overlayer is reported. The surface‐engineered hematite nanostructure exhibits significantly improved PEC performance as compared to untreated α‐Fe 2 O 3 , with an increase in the maximum incident photon‐to‐current efficiency (IPCE) of nearly 400% at 350 nm. While addition of the TiO 2 overlayer did not alter the lifetime of photoexcited charge carriers, as evidenced from transient absorption spectroscopy, it is found that the presence of TiO 2 could enhance oxygen electrocatalysis by interfacial electron enrichment, largely attributed to enhanced O(2 p )−Fe(3 d ) hybridization. Moreover, the interfacial electronic structure revealed from XANES measurements of the α‐Fe 2 O 3 /TiO 2 nanorods suggests that photoexcited holes in α‐Fe 2 O 3 may efficiently transfer through the TiO 2 overlayer to the electrolyte while electrons migrate to the external circuit along the one‐dimensional nanorods, thereby promoting charge separation and enhancing PEC splitting of water.