Morphology and Doping Engineering of Sn-Doped Hematite Nanowire Photoanodes.
High-temperature activation has been commonly used to boost the photoelectrochemical (PEC) performance of hematite nanowires for water oxidation, by inducing Sn diffusion from fluorine-doped tin oxide (FTO) substrate into hematite. Yet, hematite nanowires thermally annealed at high temperature suffer from two major drawbacks that negatively affect their performance. First, the structural deformation reduces light absorption capability of nanowire. Second, this "passive" doping method leads to nonuniform distribution of Sn dopant in nanowire and limits the Sn doping concentration. Both factors impair the electrochemical properties of hematite nanowire. Here we demonstrate a silica encapsulation method that is able to simultaneously retain the hematite nanowire morphology even after high-temperature calcination at 800 °C and improve the concentration and uniformity of dopant distribution along the nanowire growth axis. The capability of retaining nanowire morphology allows tuning the nanowire length for optimal light absorption. Uniform distribution of Sn doping enhances the donor density and charge transport of hematite nanowire. The morphology and doping engineered hematite nanowire photoanode decorated with a cobalt oxide-based oxygen evolution reaction (OER) catalyst achieves an outstanding photocurrent density of 2.2 mA cm-2at 0.23 V vs Ag/AgCl. This work provides important insights on how the morphology and doping uniformity of hematite photoanodes affect their PEC performance.
KLGHEI of Environment and Energy Chemistry, MOE of the Key Laboratory of Bioinorganic and Synthetic Chemistry, MOE of the Key Laboratory of Bioinorganic and Synthetic Chemistry, The Key Lab of Low-carbon Chemistry & Energy Conservation of Guangdong Province, School of Chemistry, Sun Yat-Sen University , Guangzhou 510275, People's Republic of China.|Department of Chemistry and Biochemistry, University of California , Santa Cruz, California 95064, United States.
Mingyang
M
Li
Department of Chemistry and Biochemistry, University of California , Santa Cruz, California 95064, United States.
Yi
Y
Yang
Department of Chemistry and Biochemistry, University of California , Santa Cruz, California 95064, United States.
Yichuan
Y
Ling
KLGHEI of Environment and Energy Chemistry, MOE of the Key Laboratory of Bioinorganic and Synthetic Chemistry, MOE of the Key Laboratory of Bioinorganic and Synthetic Chemistry, The Key Lab of Low-carbon Chemistry & Energy Conservation of Guangdong Province, School of Chemistry, Sun Yat-Sen University , Guangzhou 510275, People's Republic of China.
Weitao
W
Qiu
KLGHEI of Environment and Energy Chemistry, MOE of the Key Laboratory of Bioinorganic and Synthetic Chemistry, MOE of the Key Laboratory of Bioinorganic and Synthetic Chemistry, The Key Lab of Low-carbon Chemistry & Energy Conservation of Guangdong Province, School of Chemistry, Sun Yat-Sen University , Guangzhou 510275, People's Republic of China.
Fuxin
F
Wang
Department of Chemistry and Biochemistry, University of California , Santa Cruz, California 95064, United States.
Tianyu
T
Liu
Department of Chemistry and Biochemistry, University of California , Santa Cruz, California 95064, United States.|Department of Chemistry, Northeastern University , Shenyang 110819, People's Republic of China.
Yu
Y
Song
Department of Chemistry, Northeastern University , Shenyang 110819, People's Republic of China.
Xiaoxia
X
Liu
KLGHEI of Environment and Energy Chemistry, MOE of the Key Laboratory of Bioinorganic and Synthetic Chemistry, MOE of the Key Laboratory of Bioinorganic and Synthetic Chemistry, The Key Lab of Low-carbon Chemistry & Energy Conservation of Guangdong Province, School of Chemistry, Sun Yat-Sen University , Guangzhou 510275, People's Republic of China.
Pingping
0000-0001-9608-770X
P
Fang
KLGHEI of Environment and Energy Chemistry, MOE of the Key Laboratory of Bioinorganic and Synthetic Chemistry, MOE of the Key Laboratory of Bioinorganic and Synthetic Chemistry, The Key Lab of Low-carbon Chemistry & Energy Conservation of Guangdong Province, School of Chemistry, Sun Yat-Sen University , Guangzhou 510275, People's Republic of China.
Yexiang
Y
Tong
Department of Chemistry and Biochemistry, University of California , Santa Cruz, California 95064, United States.
Yat
0000-0002-8058-2084
Y
Li
Hematite; dopant engineering; morphology engineering; photoanode; water oxidation