Enhancing Photocatalytic β-O-4 Bond Cleavage in Lignin Model Compounds by Silver-Exchanged Cadmium Sulfide

Abstract

Photocatalytic conversion of lignocellulose to valuable aromatics has significant potential for applications in biorefineries. The photocatalyst efficiency of lignocellulose conversion is typically limited by the buffering redox system in combination with oxidation and reduction of the photoexcited holes and electrons, respectively, which ensures high charge-recombination rates. Herein, Ag+-exchanged CdS is employed for easy photoexcited electron transfer to the oxidized intermediate, which results in a marked increase in the conversion yield with high product selectivity under mild reaction conditions without any additives. The conversion yield of the lignin model compound under 6 W blue LED illumination is nearly 100% and only cleaved aromatic compounds are formed. The efficient photoredox CdS catalyst obtained via photoexcited electron–hole coupled transfer derived from an appropriate Ag+ exchange affords a promising method for lignocellulose conversion with reduced energy consumption.

Control of selectivity in organic synthesis via heterogeneous photocatalysis under visible light

“…CdS-based photocatalysts present satisfactory photocatalytic performance towards the cleavage of the β-O-4 bond as well [157][158][159][160]. Especially, CdS quantum dots (QDs) with the size of 4.4 nm demonstrate the production of acetophenone and phenol in stoichiometric amounts with high yields (> 90%), four times higher than that of the nanoparticle counterpart [157].…”

Striding the threshold of photocatalytic lignin-first biorefining via a bottom-up approach: from model compounds to realistic lignin

“…Taking advantage of the full sunlight spectrum, the chemical composition, crystal, and morphological structures also can be tuned to possess the excellent photon response. 77 The metal sulfides that can perform the one-pot cleavage of β-O-4′ linkage mainly include ZnIn 2 S 4 , 44 oxidized Ni/CdS nanosheet, 78 zinc blende structured CdS NPs, 79 Ag + -exchanged wurtzite CdS, 80 and Zn 4 In 2 S 7 . 81…”

“…8a and b). 80 It was witnessed that an appropriate Ag + exchange afforded facile photoexcited electron transfer to the oxidized intermediate for manipulating the product selectivity (Fig. 8c).…”

Highly Efficient Ag3PO4/g-C3N4 Z-Scheme Photocatalyst for Its Enhanced Photocatalytic Performance in Degradation of Rhodamine B and Phenol

“…With the rapid development of industry, environmental pollution caused by industrial wastewater is becoming increasingly serious. Photocatalysis is an effective technology to degrade pollutants in water, which has been widely researched [ 1 , 2 ]. However, one-component semiconductor photocatalysts always face various defects, such as low visible-light availability and easy recombination of photogenerated charges.…”