Enhancing visible-light-driven NO oxidation through molecular‐level insights of dye-loaded sea sands

Natural minerals,abundant and easily obtained through simple physical processing,offer a cost-effective and environmentally friendly solution for dyeing wastewater disposal and air pollution treatment.This study investigates the photocatalytic removal of NO using natural different types of dyes,loaded on natural sand,under visible light illumination.By examining various coating concentrations of dyes and sand weights,we discovered that sand loaded with Rhodamine B(RhB)exhibits high activity for the photo-oxidation of NO.A combination results of X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),Fourier transform infrared spectroscopy(FTIR)and thermogravimetric(TG)analyses confirm the presence of SiO_(2),CaCO_(3),Al_(2)O_(3)and iron oxides as the main components of the sand.Furthermore,studying RhB-loaded individual components reveals that CaCO_(3)plays a crucial role in enhancing the NO removal rate.Experimental results and theoretical calculations demonstrate the establishment of a directional charge transfer channel from CaCO_(3)to RhB,facilitating the adsorption and activation of molecular NO and O_(2).This work not only promotes the utilization of natural mineral resources but also enriches the fields of environmental photochemistry and semiconductor photocatalysis.

Polyoxometalate-organic cage with{Ni_(4)SiW_(9)}node for photocatalytic hydrogen evolution

The design and syntheses of metal-organic cages(MOCs)based on polyoxometalates(POMs)building blocks have attracted increasing attention due to their intriguing molecular architectures and physicochemical properties.In this work,we have successfully synthesized and systematically characterized a tetrahedral polyoxometalate-based organic cage(POC),K_(3)Na_(17)H_(12)[(C_(4)H_(6)O_(6))_(6)[Ni_(4)(OH)_(3)(A-α-SiW_(9)O_(34))]_(4)]·96H_(2)O(Ni_(16)L_(6)(SiW_(9))_(4)),using tritopic Ni_(4)-substituted Keggin cluster(Ni_(4)SiW_(9))as nodes and flexible L-(+)-tartaric acid ligands as linkers.The resulting POC tetrahedron has been firstly investigated as efficient catalyst for visible-light-driven hydrogen production,achieving a turnover number of 15,500 after 96-h photocatalysis.Such high catalytic performance of Ni_(16)L_(6)(SiW_(9))_(4)POC catalyst could be attributed to its unique cage structure,thereby offering more efficient catalytic component accessibility.In addition,spectroscopic analyses illustrated the photocatalytic mechanism and the structural stability of the TBA-Ni_(16)L_(6)(SiW_(9))_(4)catalyst during the photocatalytic process.