The Hole‐Tunneling Heterojunction of Hematite‐Based Photoanodes Accelerates Photosynthetic Reaction

Abstract

Single‐atom metal‐insulator‐semiconductor (SMIS) heterojunctions based on Sn‐doped Fe2O3 nanorods (SF NRs) were designed by combining atomic deposition of an Al2O3 overlayer with chemical grafting of a RuOx hole‐collector for efficient CO2‐to‐syngas conversion. The RuOx‐Al2O3‐SF photoanode with a 3.0 nm thick Al2O3 overlayer gave a >5‐fold‐enhanced IPCE value of 52.0 % under 370 nm light irradiation at 1.2 V vs. Ag/AgCl, compared to the bare SF NRs. The dielectric field mediated the charge dynamics at the Al2O3/SF NRs interface. Accumulation of long‐lived holes on the surface of the SF NRs photoabsorber aids fast tunneling transfer of hot holes to single‐atom RuOx species, accelerating the O2‐evolving reaction kinetics. The maximal CO‐evolution rate of 265.3 mmol g−1 h−1 was achieved by integration of double SIMS‐3 photoanodes with a single‐atom Ni‐doped graphene CO2‐reduction‐catalyst cathode; an overall quantum efficiency of 5.7 % was recorded under 450 nm light irradiation.

Metal Halide Perovskite Based Heterojunction Photocatalysts

“…In photoelectrocatalysis (PEC), the applied external electric field promotes charge separation and increases redox reaction rates, thus improving the overall solar‐to‐fuel conversion efficiency. Constructing a photoelectrode with a metal‐insulator‐semiconductor heterostructure could mediate the charge dynamics process and further promote the solar to energy conversion efficiency [69] . Besides electric fields, other external triggers, including mechanical stress, microwaves, magnetic field, and/or coupled fields, could improve the catalytic performance of MHPs from the inside out.…”

“…Constructing a photoelectrode with a metal-insulator-semiconductor heterostructure could mediate the charge dynamics process and further promote the solar to energy conversion efficiency. [69] Besides electric fields, other external triggers, including mechanical stress, microwaves, magnetic field, and/or coupled fields, could improve the catalytic performance of MHPs from the inside out. For example, with an external mechanical force, a built-in electric field will be created in the MAPbI 3 to effectively separate the photogenerated charge carriers, thus enhancing the final photoactivity.…”

Photocatalytic CO2conversion: from C1 products to multi-carbon oxygenates

“…37 Copyright 2019, Wiley-VCH. (i) Time course for the formation of gaseous products in the different cells at 2.4 V. 38 Copyright 2021, Wiley-VCH.…”

Efficient charge migration in TiO2@PB nanorod arrays with core–shell structure for photoelectrochemical water splitting

“…6 A PEC reaction system is a bionic system which simulates the behaviour of plants in nature to absorb and convert solar energy for hydrogen production. Therefore, designing photocatalysts of high-performance through an economically viable approach is of great importance; 7,8 semiconductor materials have been widely used in PEC water splitting owing to their excellent chemical, physical and electrical properties. [9][10][11][12] Among these semiconductor candidates, TiO 2 is a promising n-type semiconductor photoanode because of its non-toxicity, photocorrosion resistance and low cost.…”