Perspective and status of polymeric graphitic carbon nitride based Z-scheme photocatalytic systems for sustainable photocatalytic water purification

Heterogeneous catalytic ozonation (HCO) processes have been widely studied for water purification. The reaction mechanisms of these processes are very complicated because of the simultaneous involvement of gas, solid, and liquid phases. Although typical reaction mechanisms have been established for HCO, some of them are only appropriate for specific systems. The divergence and deficiency in mechanisms hinders the development of novel active catalysts. This critical review compares the various existing mechanisms and categorizes the catalytic oxidation of HCO into radical-based oxidation and nonradical oxidation processes with an in-depth discussion. The catalytic active sites and adsorption behaviors of O3 molecules on the catalyst surface are regarded as the key clues for further elucidating the O3 activation processes, evolution of reactive oxygen species (ROS) or organic oxidation pathways. Moreover, the detection methods of the ROS produced in both types of oxidations and their roles in the destruction of organics are reviewed with discussion of some specific problems among them, including the scavengers selection, experiment results analysis as well as some questionable conclusions. Finally, alternative strategies for the systematic investigation of the HCO mechanism and the prospects for future studies are envisaged.

Reactive Oxygen Species and Catalytic Active Sites in Heterogeneous Catalytic Ozonation for Water Purification

Assembly of AgI nanoparticles and ultrathin g-C3N4 nanosheets codecorated Bi2WO6 direct dual Z-scheme photocatalyst: An efficient, sustainable and heterogeneous catalyst with enhanced photocatalytic performance

Novel S-scheme 2D/2D BiOBr/g-C3N4 heterojunctions with enhanced photocatalytic activity

Peracetic acid (PAA) is increasingly used as an alternative disinfectant and its advanced oxidation processes (AOPs) could be useful for pollutant degradation. Co(II) or Co(III) can activate PAA to produce acetyloxyl (CH3C(O)O•) and acetylperoxyl (CH3C(O)OO•) radicals with little •OH radical formation, and Co(II)/Co(III) is cycled. For the first time, this study determined the reaction rates of PAA with Co(II) (kPAA,Co(II) = 1.70 × 101 to 6.67 × 102 M-1·s-1) and Co(III) (kPAA,Co(III) = 3.91 × 100 to 4.57 × 102 M-1·s-1) ions over the initial pH 3.0-8.2 and evaluated 30 different aromatic organic compounds for degradation by Co/PAA. In-depth investigation confirmed that CH3C(O)OO• is the key reactive species under Co/PAA for compound degradation. Assessing the structure-activity relationship between compounds' molecular descriptors and pseudo-first-order degradation rate constants (k'PAA• in s-1) by Co/PAA showed the number of ring atoms, EHOMO, softness, and ionization potential to be the most influential, strongly suggesting the electron transfer mechanism from aromatic compounds to the acetylperoxyl radical. The radical production and compound degradation in Co/PAA are most efficient in the intermediate pH range and can be influenced by water matrix constituents of bicarbonate, phosphate, and humic acids. These results significantly improve the knowledge regarding the acetylperoxyl radical from PAA and will be useful for further development and applications of PAA-based AOPs.

Cobalt/Peracetic Acid: Advanced Oxidation of Aromatic Organic Compounds by Acetylperoxyl Radicals.

Highly efficient H2 production over NiCo2O4 decorated g-C3N4 by photocatalytic water reduction

N-dependent ozonation efficiency over nitrogen-containing heterocyclic contaminants: A combined density functional theory study on reaction kinetics and degradation pathways

Binran Zhao

Papers

Highly efficient H2 production over NiCo2O4 decorated g-C3N4 by photocatalytic water reduction

N-dependent ozonation efficiency over nitrogen-containing heterocyclic contaminants: A combined density functional theory study on reaction kinetics and degradation pathways

In-situ synthesis of N, S co-doped hollow carbon microspheres for efficient catalytic oxidation of organic contaminants