TY - JOUR
T1 - Stimuli-responsive heterojunctions based photo-electrocatalytic membrane reactors for reactive filtration of persistent organic pollutants
AU - Kumari, Priyanka
AU - Bahadur, Nupur
AU - Conlan, Xavier A.
AU - Zeng, Xiangkang
AU - Kong, Lingxue
AU - O'Dell, Luke A.
AU - Sadek, Abu
AU - Merenda, Andrea
AU - Dumée, Ludovic F.
N1 - Funding Information:
This work was performed in part at the Melbourne Centre for Nanofabrication (MCN) in the Victorian Node of the Australian National Fabrication Facility (ANFF). The authors acknowledge the facilities, and the scientific and technical assistance of the RMIT University's Microscopy & Microanalysis Facility, a linked laboratory of the Microscopy Australia. Dr Ludovic Dumée acknowledges the support from Khalifa University through project RC2-2019-007. The authors would like to acknowledge Dr Majid Laleh for the voltammetry measurements. The Deakin University Advanced Characterisation Facility is also acknowledged. AM would like to acknowledge the Australian Research Council for financial support (DP200100313).
Funding Information:
This work was performed in part at the Melbourne Centre for Nanofabrication (MCN) in the Victorian Node of the Australian National Fabrication Facility (ANFF). The authors acknowledge the facilities, and the scientific and technical assistance of the RMIT University's Microscopy & Microanalysis Facility, a linked laboratory of the Microscopy Australia. Dr Ludovic Dumée acknowledges the support from Khalifa University through project RC2-2019-007. The authors would like to acknowledge Dr Majid Laleh for the voltammetry measurements. The Deakin University Advanced Characterisation Facility is also acknowledged. AM would like to acknowledge the Australian Research Council for financial support (DP200100313).
Publisher Copyright:
© 2022 Elsevier B.V.
PY - 2023/1/15
Y1 - 2023/1/15
N2 - The design of semiconducting metal oxide heterojunctions is promising to overcome conventional limitations associated to photocatalysis or electrocatalysis, such as fast recombination of electron-hole pairs and poor long-term stability leading to low catalytic performance. A route to tackle this issue is to design catalysts at the atomic levels by arranging order and controlling nanoscale interfaces to yield catalytic materials with greater response rates and stability to dissolution or corrosion. The present study focuses on the formation of such nanoscale heterojunctions between TiO2 and ZnO via atomic layer deposition across conductive and porous stainless-steel substrates to develop enhanced photo-electro-responsive catalytic membrane reactors. The heterojunction nano-sheet based structures produced higher density of electron and hole pairs and offered efficient separation of charges, longer lifetime of photo-generated electrons compared to single metal oxides, resulting in enhanced photocurrent efficiency. The tailoring of both the nanoscale dimensions of the metal oxide layers and the stacking of these inorganic nano-sheets led to the development of multi-heterojunctions, of a few tens of nanometres, deposited across conductive porous substrates. The high electron mobility across the heterojunction nano-sheets increased the oxygen evolution potential from 1.4 to 1.7 eV, leading to enhanced electrochemical reactions, as well as offered photocurrent densities 2–3 times higher than pristine single metal oxide membranes. The formation of type II heterojunction structures between TiO2 and ZnO leads to band alignment at the interface, yielding an efficient charge separation mechanism and high catalytic performance. A prototype of novel cross-flow filtration module was designed in this study to support the coupling of photo-electrocatalysis on the membrane surface and simultaneous pressure driven membrane processes. The designed 3D printed modules demonstrated highly enhanced degradation of several persistent organic pollutants, leading to reactivity up to 75 × 10−3 min−1 up to 500 % greater compared to single metal oxides generated with the same conditions. The intimate and synergistic interactions across the stacked metal oxide nano-sheets enabled high catalytic efficiency and stability, opening new avenues stimuli-responsive membranes scale up and implementation in wastewater remediation and compact reactors design, where sieving and reactivity are of prime importance.
AB - The design of semiconducting metal oxide heterojunctions is promising to overcome conventional limitations associated to photocatalysis or electrocatalysis, such as fast recombination of electron-hole pairs and poor long-term stability leading to low catalytic performance. A route to tackle this issue is to design catalysts at the atomic levels by arranging order and controlling nanoscale interfaces to yield catalytic materials with greater response rates and stability to dissolution or corrosion. The present study focuses on the formation of such nanoscale heterojunctions between TiO2 and ZnO via atomic layer deposition across conductive and porous stainless-steel substrates to develop enhanced photo-electro-responsive catalytic membrane reactors. The heterojunction nano-sheet based structures produced higher density of electron and hole pairs and offered efficient separation of charges, longer lifetime of photo-generated electrons compared to single metal oxides, resulting in enhanced photocurrent efficiency. The tailoring of both the nanoscale dimensions of the metal oxide layers and the stacking of these inorganic nano-sheets led to the development of multi-heterojunctions, of a few tens of nanometres, deposited across conductive porous substrates. The high electron mobility across the heterojunction nano-sheets increased the oxygen evolution potential from 1.4 to 1.7 eV, leading to enhanced electrochemical reactions, as well as offered photocurrent densities 2–3 times higher than pristine single metal oxide membranes. The formation of type II heterojunction structures between TiO2 and ZnO leads to band alignment at the interface, yielding an efficient charge separation mechanism and high catalytic performance. A prototype of novel cross-flow filtration module was designed in this study to support the coupling of photo-electrocatalysis on the membrane surface and simultaneous pressure driven membrane processes. The designed 3D printed modules demonstrated highly enhanced degradation of several persistent organic pollutants, leading to reactivity up to 75 × 10−3 min−1 up to 500 % greater compared to single metal oxides generated with the same conditions. The intimate and synergistic interactions across the stacked metal oxide nano-sheets enabled high catalytic efficiency and stability, opening new avenues stimuli-responsive membranes scale up and implementation in wastewater remediation and compact reactors design, where sieving and reactivity are of prime importance.
KW - Heterojunctions
KW - Interfacial charge transfer
KW - Membrane catalytic reactor
KW - Nanoscale arrangement
KW - Photo-electrocatalysis
UR - http://www.scopus.com/inward/record.url?scp=85138640961&partnerID=8YFLogxK
U2 - 10.1016/j.cej.2022.139374
DO - 10.1016/j.cej.2022.139374
M3 - Article
AN - SCOPUS:85138640961
SN - 1385-8947
VL - 452
JO - Chemical Engineering Journal
JF - Chemical Engineering Journal
M1 - 139374
ER -