Preparation of Peanut Shell Cellulose Double-Network Hydrogel and Its Adsorption Capacity for Methylene Blue

To achieve optimal recovery and value-added utilisation of cellulose in peanut shells,the cellulose in peanut shells was first extracted using the sodium hydroxide-sodium chlorite method.Then,cellulose hydrogel was prepared by graft copolymerisation using N,N’-methylenebisacrylamide as the cross-linking agent,sodium persulfate as the initiator,and acrylic acid as the monomer.Orthogonal optimisation experiments were designed to obtain optimal process parameters for hydrogel preparation with the cellulose dosage of 0.40 g,initiator dosage of 0.20 g,polymerisation temperature of 70°C,cross-linking agent of 0.25 g,and monomer dosage of 3.0 mL.The effect of initiator dosage on hydrogel synthesis was the most significant,followed by monomer dosage and reaction temperature.Characterisation using X-ray diffraction analysis and scanning electron microscopy revealed that the hydrogel was amorphous and exhibited a distinct three-dimensional double network structure.Hydrogel swelling kinetic analysis showed that the hydrogel swelling process was divided into three stages,and fitted the Schott secondary swelling kinetic model.The prepared hydrogel had a good adsorption effect on methylene blue;the adsorption of methylene blue by the hydrogel was 1.259 mg/g at 25°C when the initial concentration of methylene blue was 5 mg/L.The adsorption kinetics of the hydrogel fit the pseudo-first-order kinetic model,pseudo-secondorder kinetic model,Eovich model and particle diffusion model.The best fitting effect was obtained with the pseudo-second-order kinetic model.The adsorption isotherm analysis of methylene blue on hydrogel showed that the adsorption process was consistent with Langmuir and Freundlich models.The correlation coefficient of the Freundlich isotherm model was higher,indicating that the adsorption of methylene blue on hydrogel was mainly chemisorption.

Preparation of Nitrogen-doped TiO2 Nanoparticle Catalyst and Its Catalytic Activity under Visible Light

做 N 的 TiC2 nanoparticle 光催化剂作为氮来源用 NH4Cl 通过一个大音阶的第五音胶化过程被准备并且在某些温度由锻烧列在后面。为结构和相片上的准备参数和他们的影响的系统的研究催化活动在下面紫外(紫外) 并且可见轻照耀被执行。多重技术(XRD， TEM， DRIF， DSC，和 XPS ) 被命令描绘水晶结构和做 N 的 TiO2 的化学绑定。它的相片催化活动被有机化合物的降级检验。在可见的光(λ 】 400nm ) 下面的准备做 N 的 TiO2 nanoparticles 的催化活动照耀被 4-chlorophenol 的分解证实，证明在做 N 的 TiO2 nanoparticle 催化剂的氮原子为可见轻催化活动负责。没有做 N，与这条修改线路准备的做 N 的 TiO2 nanoparticle 催化剂与 TiO2 相对照在紫外照耀下面展出更高催化的活动。这里的做的氮在 TiO2 格子的空隙的地点被定位，这被建议。