Synthesis and comparative study of the structural and optical properties of binary ZnO-based composites for environmental applications

Abstract

The development of photoactive systems to solve serious environmental problems is a key objective of researchers and remains a real challenge.

Green Synthesis of TiO2 Using Impatiens rothii Hook.f. Leaf Extract for Efficient Removal of Methylene Blue Dye

“…Hydroxyl radicals, which are powerful oxidants, can react with organic pollutants and degrade them to environmentally harmless products . Generally, the following steps take place in photocatalysis of organic pollutants (1) absorption of photon energy and excitation of electron to the conduction band, (2) reduction, (3) oxidation, and (4) pollutant degradation as given in eqs –. ,− …”

“…Hydroxyl radicals, which are powerful oxidants, can react with organic pollutants and degrade them to environmentally harmless products . Generally, the following steps take place in photocatalysis of organic pollutants (1) absorption of photon energy and excitation of electron to the conduction band, (2) reduction, (3) oxidation, and (4) pollutant degradation as given in eqs –. ,− IL − Ti O 2 + hv → IL − Ti O 2 ( normalh VB + + normale CB − ) e CB − + O 2 → O 2 • − false) O 2 • − + H + → HO 2 • 2 HO 2 • → H 2 O 2 + O 2 2 HO 2 • → H 2 O 2 + O 2 • − → OH • + O 2 + OH − …”

“…One toxic and nonbiodegradable organic chemical that is frequently utilized in the textile industries is methylene blue (MB). Additionally, due to its planar shape, it is very soluble in water . Therefore, the reprocessing and treatment of wastewater is the primary activity to reduce environmental pollution and avoid the shortage of a clean water supply.…”

Croton macrostachyus Leaf Extract-Mediated Green Synthesis of ZnO Nanoparticles and ZnO/CuO Nanocomposites for the Enhanced Photodegradation of Methylene Blue Dye with the COMSOL Simulation Model

“…The generated highly reactive radicals readily oxidize and degrade dye molecules. The main reactions involved in the photodegradation process can be described by the following equations normalZ normaln normalO / normalC normalu normalO + h v → normalZ normaln normalO / normalC normalu normalO [ e ( C B ) − + h ( V B ) + ] normalZ normaln normalO / normalC normalu normalO [ e ( C B ) − + h ( V B ) + ] → normalZ normaln normalO ( e ( C B ) − ) + normalC normalu normalO ( h ( V B ) + ) Z n O ( e ( C B ) − …”

“…The generated highly reactive radicals readily oxidize and degrade dye molecules. The main reactions involved in the photodegradation process can be described by the following equations …”