Dear Colleagues,

Catalysts in heterogeneous catalysis are in a different phase from the reactants. Heterogeneous photocatalysis encompasses a wide range of processes, including gaseous pollutant elimination, water detoxification, metal deposition, ¹⁸O₂-¹⁶O₂ and deuterium-alkane isotopic exchange, hydrogen transfer, dehydrogenation, and mild or total oxidation.

Transition metal oxides and semiconductors are the main types of heterogeneous photocatalysts. Semiconductors have a gap energy region where no energy level can propagate the recombination of an electron and hole made by photoactivation in the solid, in contrast to metals, which may have a conjunction of electronic states. The band gap could be defined as the difference in energy between a semiconductor's filled valence band and the empty conduction band in its MO diagram . An electron excites from the valence band to the conduction band, forming an electron hole in the valence band, when a semiconductor absorbs a photon with energy equal to or greater than the band gap of the material . The excited hole and electron can combine once more and release the energy from the electron's excitation as heat. Exciton recombination of this type is not advantageous and exhibits higher levels of expense efficacious .

Probably the most used photocatalysts contain some limitations because of the proven fact that they show photocatalytic influence in the UV region, which is due to the large band gaps among the valence and conduction bands. Because of that, these materials need higher energy light founts. Furthermore, another item contains the kinetics relevant to the recombination of photo-generated electrons/hole pairs and the photocatalytic destruction process .

The synthesis of a photocatalytic adsorbent included the combination of various guest compounds (GMs) like carbon dots (CD) right into a metal-organic framework (MOF) or organometallic complexes utilizing the solvothermal, hydrothermal, etc technique. Characterization of the resulting GM@MOF was conducted using different analytical methods, including X-ray-based microscopic along with spectroscopic techniques, electrochemical impedance spectroscopy, photoluminescence (PL), TGA, DRS, FT-IR, and UV–Vis analysis. The adsorbent demonstrated special photocatalytic activity, achieving the removal of pollutants under visible light.

The analysis detected the agents that affect the demolition and determined optimum conditions for the procedure, including pH values for pollution, a photocatalyst density, and an H₂O₂ density range. Reactive oxidative species for instance ⋅OH and ⋅O₂ were known through the inspection of various scavengers. Also, the adsorption isotherm and kinetic studies show that the synthesized photocatalyst works as a fruitful adsorbent, with maximum adsorption capacities for contaminations, while also helping as a photocatalytic factor for removal goals.

Looking forward to your nice contribution.

Dr.Payam Hayati

Section Editor

Fenton-like degradation; Metal-organic frameworks; Heterogenous photocatalysts; Coordination polymers (CPs); Nanostructure; Sunlight active materials; Morphology; Crystal structure; Response surface methodology (RSM); Topology