Magnetic Field-Assisted Photoelectrochemical Water Splitting: The Photoelectrodes Have Weaker Nonradiative Recombination of Carrier

Abstract

The manipulation of photoelectrodes' electron− hole pairs toward low recombination is the fundamental strategy to achieve high solar-to-hydrogen conversion efficiency in photoelectrochemical (PEC) water splitting cells. Herein, we demonstrate that a magnet placed parallel to a photoelectrode can improve the water splitting activity of typical BiVO 4 and α-Fe 2 O 3 photoanodes as well as Cu 2 O/CuO and p-Si(111) photocathodes by restraining the nonradiative recombination of their carrier. Our investigations indicate that magnetic field-assisted PEC water splitting is a more effective approach than the conventional PEC water splitting. Magnetic field assistance provides a new, effective, and general strategy to improve the activity of photoelectrodes for solar water splitting and the other PEC reactions.

Enhanced Photodegradation in Metal Oxide Nanowires with Co-Doped Surfaces under a Low Magnetic Field

“…By contrast, the bare ZnO NWs with low MCD signals indicated that the minimal spin polarization in the bare ZnO NWs may lead to an indistinguishable magneto-PD effect. In addition, Yang et al, (2021) revealed that magnetic fields can weaken the nonradiative recombination of photoelectrodes’ carriers regardless of their ferromagnetic properties, contributing to improved photoelectrochemical reactions . However, the absence of a noticeable magneto-PD effect in the bare ZnO NWs herein indicated that the reported mechanism was inapplicable in our situation.…”

“…In addition, Yang et al, (2021) revealed that magnetic fields can weaken the nonradiative recombination of photoelectrodes' carriers regardless of their ferromagnetic properties, contributing to improved photoelectrochemical reactions. 31 However, the absence of a noticeable magneto-PD effect in the bare ZnO NWs herein indicated that the reported mechanism was inapplicable in our situation. Furthermore, for the surface photocatalytic reaction, the spin-polarized electrons had a considerable inhibitory effect on the recombination of active species (free radicals).…”

Photocatalytic Conversion of Plastic Waste: From Photodegradation to Photosynthesis

“…In addition, the coupling of photocatalysis with external fields (e.g., electric fields, thermal fields, magnetic fields, and ultrasonic radiation) is also worth considering, because it may produce synergistic effects that can potentially overcome the intrinsic low conversion rates of single photocatalytic process. [216][217][218] External fields can generate additional driving forces to promote the charge carrier transfer and separation, and consequently the photocatalytic efficiency. Reproduced with permission.…”

Advances in Magnetic‐Field Assisted Photoelectrochemical Systems for Highly Efficient Conversion of Renewable Energy

“…Consequently, the positive effect of magnetic field on separation and transfer characteristics of charge will lead to the reduction of photoelectrodes overpotential. [ 63 ]…”