Efficient Chemical-Free Degradation of Waterborne Micropollutants with an Immobilized Dual-Porous TiO₂ Photocatalyst

Abstract

Photocatalytic advanced oxidation processes (AOPs) promise a chemical-free route to energy-efficient degradation of waterborne micropollutants if long-standing mass transfer and light management issues can be overcome. Herein, we developed a dual-porous photocatalytic system consisting of a mesoporous (i.e., 2−50 nm pores) TiO 2 (P25) photocatalyst supported on macroporous (i.e., >50 nm pores) fused quartz fibers (P25/QF). Our reusable photocatalytic AOP reduces chemical consumption and exhibits excellent energy efficiency, demonstrated by degrading various pharmaceutical compounds (acetaminophen, sulfamethoxazole, and carbamazepine) in natural waters with electrical energy per order (E EO ) values of 4.07, 0.96, and 1.35 kWh/m 3 , respectively. Compared to the conventional H 2 O 2 /UVC AOP, our photocatalytic AOP can treat water without chemical additives while reducing energy consumption by over 2800%. We examine these improvements based on mass transport and optical (UVA and UVC) transmittance and demonstrate that the enhancements scale with increasing flow rate.

Cooperative Design of the Ag3PO4/NH2-MIL-88B (Fe/Co) Heterojunction Integrated with Conductive Polypyrrole for Advanced Photocatalytic Water Purification

“…With the growing concerns about aggravating water pollution, research efforts have been made on the development of efficient purification methods; particularly, a photocatalytic system applying metal–organic frameworks (MOFs) has drawn focused attention during the past decade. − MOFs consist of metal clusters linked with organic ligands, forming highly porous crystals, and have been explored for various applications with their advantages of high surface area, chemical tolerability, and suitable band energy as practical photocatalysts. − MOF-based photocatalysts have been developed in various composite forms including films, fibers, and foams, as the photocatalyst itself in the powdery form is inconvenient to recover after use and can cause secondary pollution. − Among the composite forms, the fibrous MOF composite can be especially advantageous for its flexibility, toughness, and large surface area that allows high loading of MOFs. − However, the higher loading of photocatalysts does not ensure efficient catalytic performance, that is, as most MOFs and fiber matrices have lower electrical conductivity, they tend to produce a low quantum yield. , Many research efforts have been made to overcome this drawback, conceiving a heterojunction system or imparting electrical conductivity. , …”

“… 11 − 13 Among the composite forms, the fibrous MOF composite can be especially advantageous for its flexibility, toughness, and large surface area that allows high loading of MOFs. 14 − 16 However, the higher loading of photocatalysts does not ensure efficient catalytic performance, that is, as most MOFs and fiber matrices have lower electrical conductivity, they tend to produce a low quantum yield. 17 , 18 Many research efforts have been made to overcome this drawback, conceiving a heterojunction system or imparting electrical conductivity.…”