Photoresponsive wood-based composite fabricated by a simple drop-coating procedure

This study reports on a photoresponsive wood prepared by entrapping phosphomolybdic acid (PMA) into a mixture of chitin/polyvinyl pyrrolidone (CS/PVP), which is anchored on the wood surface. A well-dispersed mixed matrix membrane was examined by SEM, and the change of surface morphology was measured by AFM. Colorimetric parameters of the samples under visible light irradiation were investigated. With the irradiation time increasing from 0 to 90 min, total color change of the sample remarkably increased from 0.7 to 42.5, verifying an excellent photoresponsive property. The interaction between the PMA particles and CS/PVP blend was investigated by using FTIR. Furthermore, the results of UV–Vis and XPS spectra revealed that the photoreduction reaction occurred, and the heteropoly blues were formed during the process of irradiation. The coating adhesion and thermal stability results demonstrated that the coating was firmly adhered to the wood substrate, and the as-prepared sample had a better heat resistance performance than the pristine wood. Owing to the superior sensitivity, accurate response and environmental protection, the future of the photoresponsive wood with visible light response looks bright with many promising application areas such as sensor, smart home and solar energy conversion.