Near infrared light-assisted photoelectrochemical conversion and environmental remediation

Abstract

Solar energy conversion to chemical energy is a practical approach to sustainable development. Despite continuous advancements in energy technologies, conversion efficiencies remain shallow and below desired levels. Most research efforts are concentrated on absorbing the UV-Vis portion of solar radiation, with relatively little attention given to the infrared segment, even though it constitutes a substantial portion of solar radiation, accounting for ∼50 %. The photon energy in the NIR (Near-Infrared) range is insufficient. It does not correspond adequately to the semiconductor bandgap energy levels required to stimulate the generation of electrons and holes. However, novel nanomaterials are being scrutinized to absorb NIR light and generate photoexcited electrons/holes, which can be utilized to transform effectively through novel electron transfer pathways. Engineering surface and bulk properties of these NIR absorbing nanomaterials and harnessing NIR radiations have shown promising results in ameliorating the light conversion, yield, and faradaic efficiencies. This review article highlights the methodology, in-depth mechanistic models, current progress, and potential of NIR light in assisting organic dye degradation (waste water treatment), H₂ production, CO₂ reductions, N₂ reduction through photocatalytic and photoelectrocatalytic pathways.