Synergistic effect of iodine doped TiO2 nanoparticle/g-C3N4 nanosheets with upgraded visible-light-sensitive performance toward highly efficient and selective photocatalytic oxidation of aromatic alcohols under blue LED irradiation

Theoretical and experimental studies on photocatalytic removal of methylene blue (MetB) from aqueous solution using oyster shell synthesized CaO nanoparticles (CaONP-O)

The development of technologies for the removal of dye from aqueous solution is most desirable if the end product is relatively green (i.e., environmentally friendly). Photodegradation (as one of such technology) and photolysis (without the catalyst) was applied to investigate the role of sol-gel synthesized calcium oxide nanoparticle (using the oyster shell as the precursor). The results obtained gave substantial evidence that calcium oxide nanoparticles catalyzed the degradation of the methylene blue dye up to a maximum percentage of 98 % removal. Degradation efficiency displayed a strong dependency on time, initial dye concentration, catalyst load, pH, and ionic strength. Chi-square and sum of square error analysis indicated that the photodegradation kinetics fitted the Langmuir-Hinshelwood, first order, and pseudo first-order models best. The half-life of the dye was significantly reduced from hours to minutes due to photocatalysis. Quantum chemical calculations indicated that the degradation proceeded through adsorption, deformation/degradation, and desorption through the chloride end of the molecule linked to the calcium active center of the catalyst. Results from Fukui functions and molecular descriptors analysis confirmed the mechanism of photocatalysis.

Construction of a 2D/2D heterojunction via integrating MoS2 on Co-doped g-C3N4 to improve photocatalytic hydrogen evolution under visible light irradiation

Schematic of the photocatalytic mechanism of the MoS₂/CoCN-3 composite with enhanced photocatalytic properties for hydrogen evolution.