Supporting Information

Supporting Information

Sn-doped Hematite Nanowires for Photoelectrochemical Water Splitting

Yichuan Ling, Gongming Wang, Damon A. Wheeler, Jin Z. Zhang, Yat Li* Department of Chemistry and Biochemistry, University of California, Santa Cruz, California 95064 *Corresponding Author. E-mail: yli@chemistry.ucsc.edu

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Synthesis of hematite nanostructures c. With 1 ml ethanol a. Without ethanol b. With 1 ml ethanol containing SnCl4

FeOOH

Sintered at 650 °C

Sintered at 800 °C

Table S1. Summary of digital pictures of FeOOH and nanostructured hematite samples prepared in (a) aqueous solution without ethanol; (b) aqueous solution mixed with 1 ml ethanol; and (c) with 1 ml ethanol containing SnCl4 (Sn precursor). FeOOH (yellow) were converted into hematite (red) after high-temperature sintering at 650 and 800 °C. The growth conditions for these hematite samples can be found in Synthetic Methods.

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Figure S1. (a) XPS survey of hematite nanowires and nanocorals sintered at 650 and 800 °C. (b) High-resolution Sn 3d XPS spectra of hematite nanowires sintered at 800 °C

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Figure S2. Dark scans collected for hematite nanowire photoanodes sintered at various temperatures in a range from 550 to 800 °C.

Figure S3. I-V curves collected for undoped hematite nanowires sintered at 800 (for 5 min) and 750 °C (for 15 min), respectively. All the samples show similar turn-on voltage around 0.65 V vs. RHE.

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Figure S4. SEM images of hematite nanostructures prepared in the presence of ethanol solution (without SnCl4). These samples were sintered at (a) 650 °C and (b) 800 °C. Scale bars are 1 µm.

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Figure S5. XRD spectra collected for hematite nanowires, nanocorals and control samples sintered at 650 and 800 °C. The blue and orange lines highlighted the diffraction peaks of αFe2O3 and SnO2, respectively. Their characteristic diffraction peaks were identified and can be indexed to α-Fe2O3 structure (JCPDS 33-0664). The SnO2 peaks are...