Alloying effect of PdCu-TiO2 in photocatalytic membrane reactor for efficient removal of humic acid foulant

Photocatalytic membrane reactor (PMR), coupling photocatalysis and membrane separation, has shown a considerable potential in foulant removal. However, the serious membrane fouling and fragile membrane stability still limit the application of current PMR systems. Here, we report a strategy that PdCu alloy deposited on TiO2, which is incorporated with polyvinylidene fluoride membrane, achieves high humic acid (HA) rejection efficiency (100%) with enhanced membrane permeation and anti-fouling performance. Detailed characterizations demonstrate that alloying effect of PdCu-TiO2 plays multiple roles in improving PMR performance: (1) providing the paired Pd-Cu sites for enhancing HA adsorption and transferring electrons from Pd-Cu sites to HA to improve photocatalytic HA removal; (2) inducing the photothermal effect due to the carrier damping, which directly enhances membrane permeation. The remarkable properties of PdCu-TiO2 membrane in PMR confirm the significance of alloying effect for treating aqueous organic pollutants.

Automated summary

The photocatalytic membrane reactor (PMR) has the potential to remove foulants effectively, but current PMR systems face limitations due to membrane fouling and instability. In this study, PdCu alloy deposited on TiO2 incorporated with a polyvinylidene fluoride membrane achieved high rejection efficiency of humic acid (HA) with improved permeation and anti-fouling performance. The alloying effect of PdCu-TiO2 played multiple roles in enhancing PMR performance, including enhancing HA adsorption and improving photocatalytic HA removal, as well as inducing a photothermal effect that enhanced membrane permeation.