In Situ Growth of ZnAl‐LDH on Biomass Carbon for Highly Efficient Photodegradation of Malachite Green (MG) From Water

ABSTRACT As a renewable new material with high void ratio, large adsorption surface area, and high adsorption rate, biomass carbon (BC) is a promising adsorbent, which has received wide attention for the degradation of dyes. However, physical adsorption cannot completely remove dyes, and there is also the risk of secondary pollution. ZnAl‐layered double hydroxide (ZnAl‐LDH) is a semiconductor photocatalyst with abundant active sites and excellent degradation efficiency. In this paper, we have designed a ZnAl‐layered double oxide@biomass carbon (ZnAl‐LDO@BC) formed by in situ grown LDH on the waste poplar wood as a synergistic adsorption and photocatalytic system. BC as a support could enhance the dispersity of layered double oxide (LDO), whereas LDO could provide photodegradation function to BC. Our studies indicate that the prepared ZnAl‐LDO@BC presents lower bandgap energy, higher surface area, and lower complexation efficiency of holes and electrons than delignified biomass (DB). As a result, ZnAl‐LDO@BC increased the removal rate of malachite green (MG) to 85.8%, which is 3.5 times higher than DB. The maximum removal rate was close to 98%, and the removal capacity was 1954 mg g −1 under an initial concentration of 200 mg L −1 of MG dye, and the possible mechanism of MG degradation was also investigated. In this study, the conversion of agroforestry wastes into high‐value materials applied to dye degradation provides a new pathway for the production of stable, sustainable, and superior photocatalytic material.