Regulation of intrinsic physicochemical properties of metal oxide nanomaterials for energy conversion and environmental detection applications

Abstract

In response to the global energy crisis and damage to humans by environmental issues, metal oxide nanomaterials (nonprecious) represent an important class of materials for energy conversion and environmental detection on account of their natural abundance, easy synthesis, low cost, and excellent stability. A majority of pristine metal oxide nanomaterials have certain shortcomings in catalysis and sensing, such as poor conductivity and wide bandgap. Fortunately, the regulation of the intrinsic physicochemical properties of metal oxide nanomaterials is a very promising approach for improving their catalytic and sensing properties for energy conversion and environmental detection. In this review, we will mainly discuss the regulation of the intrinsic physicochemical properties, namely, shape and size, defects, crystal facets, and ion cycles of metal oxide nanomaterials, with a majority of applications involving photocatalytic water splitting and CO₂ reduction, electrocatalytic water splitting, heavy metal ion (HMI) detection, and metal oxide gas sensors. Density functional theory (DFT) calculations and X-ray absorption fine-structure (XAFS) spectroscopy analysis have been used to evaluate the effects of regulation of the intrinsic physicochemical properties of metal oxide nanomaterials, as well as to further identify the relationship between the intrinsic physicochemical properties and their enhanced catalytic and sensing properties with regard to energy conversion and environmental detection. Finally, some unresolved problems associated with future perspectives in this field are discussed, inspiring further development of the intrinsic physicochemical properties of metal oxide nanomaterials.