Peirong Chen

The artificial photocatalytic degradation of organic pollutants has emerged as a promising approach to purifying the water environment. The core issue of this ongoing research is to construct efficient but easily recyclable photocatalysts without quadratic harm. Here, we report an eco-friendly photocatalyst with in situ generated TiO₂ quantum dots (TQDs) on natural cotton cellulose (CC) by a simple one-step hydrothermal method. The porous fine structure and abundant hydroxyl groups control the shape growth and improve the stability of nanoparticles, making natural CC suitable for TQDs. The TQDs/CC photocatalyst was synthesized without the chemical modification of the TQDs. FE-SEM and TEM results showed that 5–6 nm TQDs are uniformly decorated on the CC surface. The long-term stability in photocatalytic activity and structure of more than ten cycles directly demonstrates the stability of CC on TQDs. With larger CC sizes, TQDs are easier to recycle. The TQDs/CC photocatalysts show impressive potential in the photocatalytic degradation of anionic methyl orange (MO) dyes and cationic rhodamine B (RhB) dyes.

Corn starch/polyvinyl alcohol (PVA) composite films containing different concentrations of tea polyphenols (TP) were fabricated by casting. Scanning electron microscopy and atomic force microscopy images showed that when the TP content was less than 8%, the films were relatively uniform, but with increasing TP concentration, the films became rougher and uneven. Fourier transform infrared, ¹³C nuclear magnetic resonance, and X‐ray diffraction techniques were used to investigate the interactions between TP, starch, and PVA. The incorporation of TP deepened the color and increased the opacity and solubility of the films. The tensile strength and elongation at break first increased and then decreased with increasing TP content. Furthermore, the addition of TP increased the antioxidant activity of the films, specifically, their ability to scavenge 2,2‐diphenyl‐1‐picrylhydrazyl and 2,2′‐azinobis (3‐ethylberizothiazoline‐6‐sulfonic acid). The addition of TP can effectively enhance the performance of starch composite films and their potential for application in antioxidant food packaging.

A novel and simple method was described for preparation of carbonaceous adsorbent (CA) from corncob under phosphoric acid conditions. The method succeeded to introduce oxygen-containing groups onto the product surface through hydrothermal carbonization (HTC) at low temperature of 160 °C. Adsorption of methylene blue (MB) was studied systematically through the effect of pH, contact time and initial dye concentrations. The MB adsorption kinetics and isotherms experiments showed that Langmuir model and pseudo-second-order model could better describe the adsorption behavior, with a maximum adsorption capacity of MB was 140.25 mg/g. The high adsorption capacity could be ascribed to the presence of surface oxygen-containing functional groups and pore channels. In conclusion, it could be a potential adsorbent in the removal of methylene blue from wastewater.