Self-assembled TiO2/MOF on corrugated paper as a recyclable and efficient composite for dual-channel dye removal

Abstract

Adsorption separation and photocatalytic techniques have emerged as effective methods to eliminate organic dyes from water environment, but the poor recycling of most powdered adsorbents and photocatalysts in aqueous solutions hinders their commercial viability. Herein, we propose an effective and reusable dye-elimination module through the bottom-up self-assembly of photocatalyst (TiO2 nanoparticles) and adsorbent (Al-fumarate) on a corrugated paper (CP) support. Results show that the hydrophilic and electrostatic interactions between the components ensure the integrity of the whole module in aqueous phase dyes, thereby ensuring its practicality and cyclic stability (10 times). Al-fumarate with a superior specific surface area of (1117.82 m2/g) and porosity (0.47 cm3/g) on the substrate serves to induce and capture the dye molecules, while TiO2 nanoparticles with a wide bandgap trigger a redox reaction to further degrade the organic pollutants. Through the synergistic effect between adsorption and photocatalytic strategies, the resultant functional CP-based composite exhibits superior dye-removal performance than other potential composite materials, reaching 98.93% degradation efficiency of congo red (CR) solution (25 mg/L), and 97.91% elimination capacity of methylene blue (MB) solution (20 mg/L). Therefore, the designed dye-elimination module can serve as a convenient, recyclable, and efficient cleaning module in practical wastewater treatment fields.