Microwave-synthesized Cu-modified g-C3N4 for efficient mold resistance of woods and bamboo

Abstract

Since multicomponent plasmonic nanoparticle (NP) assisted semiconductors exhibit enhanced photocatalytic performances, their application as anti-mold agents for wood and bamboo products has aroused great interest. Herein, Cu NPs were grown on the surface of graphitic carbon nitride (CN) via the microwave treatment of Cu²⁺/CN solutions. CN/Cu composites were loaded on beech wood (BW), pine wood (PW), oak wood (OW), and bamboo via vacuum impregnation. The morphology, crystalline phase, porosity, element distribution and ratio, and elemental chemical state of CN/Cu and CN/Cu-loaded woods and bamboo were systematically investigated. Low leaching rates (6.79–7.88%) of CN/Cu from the matrix demonstrated the excellent stability of loading. Woods and bamboo uniformly loaded with CN/Cu presented the inhibition efficiency of Aspergillus niger after cultivating under visible light for 28 days, i.e., grade 1 for loaded woods and grade 2 for loaded bamboo. By combining the evaluation of band gap, electron paramagnetic resonance and photocurrent of CN/Cu composites, the integration of Cu with CN decreased the photo-generated electron–hole recombination rate and presented a wider range of visible light response. Moreover, the synergistic antifungal mechanism of CN/Cu composites under visible light was proposed. This work created a pathway to develop photocatalytic anti-mold agents for the preservation of woods and bamboo.