Recent advances in the built-in electric-field-assisted photocatalytic dry reforming of methane

Methane (CH4) and carbon dioxide (CO2) are two major greenhouse gases that contribute to global warming. The dry reforming of methane (DRM) is an ideal method for dealing with the greenhouse effect because it simultaneously consumes CH4 and CO2 to produce syngas. However, conventional technologies require high temperatures to trigger the DRM process owing to the high energy barriers associated with activating CH4 and CO2. While the development of photocatalysts provides opportunities for initiating the DRM under mild conditions, photocatalytic efficiency nonetheless remains unsatisfactory, which is largely attributable to rapid photoexcited charge-carrier recombination. A promising strategy for overcoming this deficiency involves constructing a built-in electric field that enhances the separation and transfer dynamics of charge carriers. This review introduces reaction mechanisms and thermal catalysts for DRM applications. The advantages of photocatalytic DRM (PDRM) and potential photocatalysts are also summarized. Recent advances have enhanced PDRM by introducing electric fields through the fabrication of photocatalysts that exhibit ferroelectric effects (ferroelectric-based photocatalysts), have heterojunction structures, or undergo localized surface plasmon resonance (LSPR). In addition, significant advanced in-situ-characterization studies and theoretical calculations are introduced along with their potential impact to provide young researchers engaged in the PDRM field with simple guidance. Finally, current challenges facing the built-in electric-field-assisted PDRM field are discussed and possible strategies proposed to encourage more in-depth research in this area.