Accelerated ZnMoO₄ photocatalytic degradation of pirimicarb under UV light mediated by peroxymonosulfate

Abstract

This paper reports the optimized synthesis of zinc molybdates by the hydrothermal method and the combination of ZnMoO4 and peroxymonosulfate (PMS) under UV irradiation for the degradation of pirimicarb. The as‐prepared ZnMoO4 photocatalyst was characterized using X‐ray diffraction, scanning electron microscopy, X‐ray photoelectron spectroscopy and UV–visible diffuse reflectance spectroscopy. The effects of operational parameters in the ZnMoO4/PMS/UV system were evaluated and the results indicated the highest performance is achieved with pH = 9.0, 1 mM PMS and 1 g l−1 ZnMoO4. The degradation efficiency of pirimicarb was 98% after 3 h in the photocatalytic process. A photodegradation mechanism is proposed based on scavenger and electron spin resonance studies to decide the main active species and by using chromatography–mass spectrometry to identify the major intermediates. Pirimicarb degradation is found to be mainly driven by holes and •O2− radicals, with the contribution of •OH and SO4•− radicals enhancing the process in the tested catalytic system. The mechanism is proposed involving two routes, dealkylation and decarbamoylation. Lastly, the zinc molybdate photocatalyst is shown to be stable, reusable and efficient in the removal of pirimicarb from real water samples in the presence of PMS, demonstrating potential application in the treatment of contaminated and/or environmental water.

First principle investigation of the exposed surfaces and morphology of β-ZnMoO4

“…In addition, it was observed that different shapes were obtained by tuning E surf for β-ZnMoO 4 , such as truncated and nontruncated rectangular, hexagonal, octahedral, and rhombic shapes matching the experimental morphologies obtained by examining the FE-SEM images. 64,67,69,71,88 These experimentally observed morphologies should be close to the equilibrium shapes under the experimental conditions. From a thermodynamic point of view, the morphology is controlled by relative stability of different surfaces, and the surface with the lowest E surf value is the main component of the corresponding morphology.…”

“…In the case of β-ZnMoO 4 , a series of experimental works have been developed in order to elucidate the shape-dependent properties of the monoclinic wolframite material, especially in the photoluminescence and photocatalysis fields. 64,67,69,71,88 However, the reasons behind the shape-dependent properties remain unclear, with the combination of theory and simulation being an alternative tool in this research area that can guide the efficient synthesis of outstanding materials. The Wulff construction was employed in this study in order to rationalize the crystal morphologies, which is related to the relative stability of the exposed surfaces.…”

“…30, [53][54][55][56][57][58][59][60][61][62][63] In particular, zinc molybdate (ZnMoO 4 ) is a representative member of these widely investigated inorganic materials due to its attractive features. 55,[64][65][66][67][68][69][70][71] The multifunctional properties of ZnMoO 4 complex ternary oxides are influenced by the surface structure. Therefore, their surface controlled synthesis is not only a rational route to study the relationship between the morphology and the surface structuredependent properties but also a feasible approach for developing highly active materials such as catalysts and sensors.…”

Photocatalytic Degradation of Ethiofencarb by a Visible Light-Driven SnIn4S8 Photocatalyst

“…The main factor in assessment of the photocatalytic activity of a semiconductor is its optical absorption properties, which depend on its band structure [ 34 , 35 , 36 ]. Thus, the UV–vis diffuse reflectance spectrum of SnIn 4 S 8 was recorded ( Figure 3 a).…”

Recent Advances in Metal-Catalyzed Alkyl–Boron (C(sp3)–C(sp2)) Suzuki-Miyaura Cross-Couplings

“…Among the different hybridized boron reagents employed in SMCs (e.g., aryl, heteroaryl, and vinylboronic acids and esters), the use of organoboron compounds with alkyl groups (sp 3 carbon) was severely limited in these coupling reactions due to competitive side reactions [39,40]. Organometallic compounds that are metalated at sp 3 Metal catalysis has had a major impact on numerous research fields from energy, biomass, environmental and water purification to synthesis of otherwise challenging and even inaccessible materials and medicinal adducts [18][19][20][21][22][23][24][25][26][27][28][29][30]. In line, the intensive research in metal catalysis has led to significant progress in borylation of primary C(sp 3 )-H bonds of unfunctionalized hydrocarbons, allowing access to a variety of C(sp 3 )-B reagents and consequent breakthroughs in C(sp 3 )-C(sp,sp 2 ,sp 3 ) cross-couplings.…”