Qi Chen,Ling Hu,Yingzhang Shi,Cheng Liu,Yidong Hou,Jinhong Bi,Jimmy C. Yu,Ling Wu
Heterogeneous photocatalytic degradation of antibiotic involves the activation of antibiotic molecules and the photocatalytic oxidation process. However, the simultaneous improvement of these processes is still a challenge. Herein, S-scheme heterojunctions consisted of Cu 2 O nanocluster with defective WO 3 nanosheets were constructed for efficient photocatalytic degradation of levofloxacin (LVX). The typical CNS-5 composite (5 wt% Cu 2 O/WO 3 ) achieves an optimal LVX degradation efficiency of 97.9% within 80 min. The spatial charge separation and enhancement of redox capacity were realized by the formation of S-scheme heterojunction between Cu 2 O and WO 3 . Moreover, their interfacial interaction would lead to the loss of lattice oxygen and the generation of W 5+ sites. It is witnessed that the C–N of piperazine ring and C O of carboxylic acid in LVX are coordinated with W 5+ sites to build the electronic bridge to activate LVX, greatly promoting the further degradation. This work highlights the important role of selective coordination activation cooperated with S-type heterojunctions for the photocatalytic degradation and offers a new view to understand the degradation of antibiotics at molecular level.
Keto-alcohols, which are traditionally produced from fossil resources with multisteps, are considered as important intermediates for diversified high-value-added fine chemical synthesis due to their involved carbonyl and hydroxyl groups. Herein, direct cellulose hydrogenolysis to C3-C4 keto-alcohol products (hydroxyacetone and 1(3)-hydroxy-2-butanone) was achieved over Ni-WOx/C catalysts with an W/Ni atom ratio of 1.0–5.0. The keto-alcohol yield was proposed to strongly depend on the W/Ni ratio and the catalyst annealing temperature. The highest keto-alcohol yield of 63% was obtained at the optimal balance of basic/acidic WOx species and metallic Ni. The introduction of Ni facilitated the formation of the basic W5+ sites, which enhanced the formation of basic sites at the Ni-WOx interface. The synergistic effect between the basic W5+ and acidic oxygen vacancy (Vö) could activate the target C–O/C═O bonds, promoting the isomerization of glucose and C3-C4 aldehyde intermediates with the assistance of the interfacial Ni. The cooperative adsorption of the −OH and −C═O groups at the Ni-O-W-Vö interface stabilized the adjacent ketone and hydroxyl groups and kept the other hydroxyl groups for hydrogenolysis, obtaining the final C3-C4 keto-alcohols. This work expanded the application of cellulosic biomass, enabling the green and sustainable synthesis of the high-value C3-C4 keto-alcohol products using lignocellulosic biomass as a raw material.