Preparation and properties of high-efficiency lignin-carbon based photocatalytic composites for the degradation of dye wastewater under visible light

Lignin-based carbon/cadmium sulfide (LCS) composite photocatalytic materials with excellent porous structures were prepared by simple carbonization and in situ precipitation using lignin from a wide range of sources as a carbon source. The CdS nanoparticles were uniformly fixed in LC, which improved the sunlight absorption ability and good stability of the photocatalyst. The effect of different factors on the pore structure of composite photocatalytic materials was investigated. The results showed that the obtained LCS composites had the maximum specific surface area (334.841 m2<middle dot>g-1) and porosity (0.4406 mL<middle dot>g-1) when the mass ratio (the lignin: the templating agent) was 2:1 and the carbonization was carried out at 600 degrees C for 1.5 h (LCS-600-1.5-2). Compared with pure CdS, the photodegradation performance of the prepared LCS under simulated sunlight (500 W Xe lamp) irradiation was significantly improved. The degradation rate of methylene blue (MB) and methyl orange/methylene blue (MO/MB) by LCS reached 91.7% and 90.8% in 2 h, respectively. The material stability test of LCS showed that LCS has good acid-base stability, and the degradation rate of MB remained above 80% after 5 cycles. The LCS prepared from lignin biomass, improved the dispersion uniformity of cadmium sulfide, reduced the recombination of photogenic electron hole, enhanced the photocatalytic performance under visible light, which greatly expanded the application of photocatalytic material.