Photoelectrochemical water splitting cell enables the conversion of solar energy into hydrogen fuel from splitting water. Although promising, the efficiency of the overall photoelectrochemical cell is often limited by water oxygen evolution reaction (OER) in the anode, which is kinetically sluggish.1 While finding more efficient and cheap (photo-)catalyst for OER is an active research area, some researchers have proposed the idea of substituting OER with oxidation of organic substances that derived from byproducts of biomass processing, e.g., ethanol, glycerol, glucose, etc. which is kinetically more favorable compared to OER. 1–4 Moreover, the oxidation of organic substances are shown to produce value-added products, e.g.: oxidation of ethanol can produce acetate and hydrogen, which are more valuable compared to ethanol.2
Hematite (α-Fe2O3) as a popular photoanode for solar water splitting has already been demonstrated for the oxidation of organic substances with higher hydrogen yield compared to the system without the addition of organic substances.5 Other metal oxide semiconductors such as TiO2 and WO3 have also been investigated in similar works.6,7 In this work, we would like to explored the possibilities of using earth-abundant bimetallic catalyst-hematite heterostructured photoanode (i.e., FeNiP/hematite) in a biomass oxidation configured with hydrogen reduction from water splitting cell in the quest to reduce the onset potential for photocurrent generated from photoanode and thus improve photoelectrochemical cell performance.
1. You, B., Liu, X., Jiang, N. & Sun, Y. J. Am. Chem. Soc. 138, 13639–13646 (2016).
2. Chen, Y. X. et al. Nat. Commun. 5, 1–6 (2014).
3. Zhang, L. et al. Nano Res. 9, 3388–3393 (2016).
4. Carraro, G. et al. Adv. Funct. Mater. 24, 372–378 (2014).
5. Iervolino, G. et al. Appl. Surf. Sci. 400, 176–183 (2017).
6. Antoniadou, M. & Lianos, P. Appl. Catal. B Environ. 99, 307–313 (2010).
7. Raptis, D., Dracopoulos, V. & Lianos, P. J. Hazard. Mater. 333, 259–264 (2017).