Computer chip-inspired design of nanocellulose/carbon dots hydrogel as superior intensifier of nano-sized photocatalyst for effective Cr(VI) removal

Hydrogel, a common carrier of photocatalyst that suffers from compromised catalytic efficiency, is still far from practical application. Herein, based on computer chip-inspired design, a novel nanocellulose/carbon dots hydrogel (NCH) was fabricated as superior intensifier instead of common carrier of sodium titanate nanofibre (STN), where carbon dots (CDs) enhanced amino group-induced adsorption for Cr(VI), promoted photocatalytic properties of STN via transferring the photogenerated electron-hole pairs and improved amino group-induced desorption for reduced product (Cr(III)) via electrostatic repulsion, showing an efficiency of 1 + 1 > 2. Adsorption and photocatalysis ex-periments demonstrated superior removal performance of the NCH incorporating STN, as shown by theoretical maximum adsorption capacity of 425.74 mg/g and kinetic constant of 0.0374 min(-1) in the photocatalytic process, which was nearly 6.6 and 7.3 times of STN. A series of experiments was conducted to confirm the novel mechanism of CDs-enhanced adsorption-photocatalysis-desorption synergy. This work not only provides new insights into the fabrication of a superior intensifier for nanosized photocatalyst, but also proposes one new mechanism of CDs -enhanced adsorption-photocatalysis-desorption synergy, which is helpful for designing and optimizing nanosized photocatalyst.

Automated summary

Based on computer chip-inspired design, a novel nanocellulose/carbon dots hydrogel (NCH) was fabricated as a superior intensifier instead of a common carrier of sodium titanate nanofibre (STN). Carbon dots enhanced adsorption for Cr(VI), promoted photocatalytic properties of STN, and improved desorption for reduced product (Cr(III)) through electrostatic repulsion, showing an efficiency of 1 + 1 > 2.