In this paper, the synergistic effect of porosity and gradient of Mo doping in BiVO photoanodes for improving charge separation and solar water oxidation performance is reported. A simple solution-based, three-step fabrication route was adopted using a layer-by-layer assembling technique. A water oxidation photocurrent of ∼1.73 mA cm at 1.23 V vs reversible hydrogen electrode in neutral pH was achieved without using any sacrificial agent or electrocatalyst. The gradient Mo doping was found to enhance charge separation efficiency, which was verified through a shift in the water oxidation onset potential cathodically to ∼200 mV. In addition, these results were further confirmed by a higher open-circuit photovoltage and flat band potential investigations. This was attributed to the surface energetics played by gradient Mo doping that served as the driving force in reducing the onset potential for water oxidation. The coupled effect of enhanced light absorption and charge separation was revealed by monitoring the difference in decoupling the water oxidation efficiencies of porous and planar Mo:BiVO photoanodes. This study demonstrated an improvement in the catalytic and charge separation efficiency of Mo:BiVO photoanodes due to the introduction of porous structured homojunctions in a gradient manner. The simple synthesis approach adopted in the present study can be utilized and scaled up in making efficient photoanodes for competent solar water oxidation cells.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6641386PMC
http://dx.doi.org/10.1021/acsomega.7b01794DOI Listing

Publication Analysis

Top Keywords

water oxidation
28
gradient doping
16
charge separation
16
solar water
12
synergistic porosity
8
porosity gradient
8
separation efficiency
8
onset potential
8
mobivo photoanodes
8
water
7

Similar Publications

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!