Grant: Discovery Grants Program - Individual

Water pollution from diverse organic contaminants and heavy metal ions poses grave threats to human and environmental health. Adsorption and photocatalysis are two highly effective techniques for removing and/or degrading various water contaminants. Building on our prior research achievements, the proposed research aims to advance the development of cost-effective, and sustainable adsorptive and photocatalytic technologies for water detoxification using (i) porous biopolymer-based composites: Low-cost adsorbents derived from natural biopolymers demonstrated high adsorption capacity and selectivity for metal ions due to the presence of electron-rich moieties. However, low porosity and weak mechanical strength limit their usage in large-scale water decontamination processes. The proposed research intends to develop new porous composite adsorbents by incorporating porous inorganic metal oxides and graphene oxide into biopolymer matrices. It is anticipated that the newly developed composite adsorbents will facilitate the effective removal of metal ions and ionizable organic contaminants from real industrial wastewater. To determine the extent of their capacity for the adsorptive removal of specific water pollutants, the structure-function relationship of the composites will be examined through a combination of experimental, spectroscopic, and theoretical methods; (ii) novel nanocarbon/metal oxide heterojunctions: Incorporating nanocarbon materials (e.g., carbon quantum dots, carbon nitride) into wide-bandgap metal oxide (e.g., TiO2) semiconductors (SCs) could significantly boost the visible-light absorption efficiency and photocatalytic activity of the wide-bandgap metal oxide SCs. Despite the great potential exhibited by nanocarbon/metal oxide heterojunctions, rational construction of these heterojunctions is exceedingly difficult. It is even more challenging to identify and verify the exact charge transfer pathway between them. The proposed research primarily concentrates on optimizing the properties (favorable bandgap and band edge positions, prolonged carrier lifetime, short carrier pathway to the surface, etc.) and photocatalytic activity of the heterojunctions by modulating the composition, loading, and interfacial interactions of nanocarbon materials and metal oxides. This research initiative will develop novel adsorptive and photocatalytic technologies for cost-effective and environmentally friendly large-scale wastewater treatment. The planned research will advance biopolymeric and carbonaceous composite synthesis and application. It will illuminate how interfaces and interfacial interactions increase composite material performance. This research will improve process economics and potential commercialization by designing, simulating, and optimizing adsorption and photocatalytic reaction processes. Finally, a unique environment for training highly qualified personnel (HQP) in both fundamental and applied research will be established.