Waveguide photoreactor enhances solar fuels photon utilization towards maximal optoelectronic - photocatalytic synergy.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 33452247.
- Also identified by DOI 10.1038/s41467-020-20613-2 and PMC identifier 7810999.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
A conventional light management approach on a photo-catalyst is to concentrate photo-intensity to enhance the catalytic rate. We present a counter-intuitive approach where light intensity is distributed below the electronic photo-saturation limit under the principle of light maximization. By operating below the saturation point of the photo-intensity induced hydroxide growth under reactant gaseous H<sub>2</sub>+CO<sub>2</sub> atmosphere, a coating of defect engineered In<sub>2</sub>O<sub>3-x</sub>(OH)<sub>y</sub> nanorod Reverse Water Gas Shift solar-fuel catalyst on an optical waveguide outperforms a coated plane by a factor of 2.2. Further, light distribution along the length of the waveguide increases optical pathlengths of the weakly absorptive green and yellow wavelengths, which increases CO product rate by a factor of 8.1-8.7 in the visible. Synergistically pairing with thinly doped silicon on the waveguide enhances the CO production rate by 27% over the visible. In addition, the persistent photoconductivity behavior of the In<sub>2</sub>O<sub>3-x</sub>(OH)<sub>y</sub> system enables CO production at a comparable rate for 2 h after turning off photo-illumination, enhancing yield with 44-62% over thermal only yield. The practical utility of persistent photocatalysis was demonstrated through outdoor solar concentrator tests, which after a day-and-night cycle showed CO yield increase of 19% over a day-light only period.