Enhancing NO degradation in visible light through plasma-treated photocatalytic substrates featuring TiO<sub>2</sub>@g-C<sub>3</sub>N<sub>4</sub> Z-scheme structure

In this study, a novel approach is introduced involving grafting and dip coating on photocatalytic substrates to create a Z-Scheme structure of TiO<sub>2</sub>@g-C<sub>3</sub>N<sub>4</sub> (TC). The synthesized photocatalyst undergoes comprehensive characterization through techniques such as XRD, SEM, XPS, FTIR, Contact Angle Goniometer, and BET analysis. Two configurations, TC coated on PVDF membrane (TC-PVDF) and TC coated on Film (TC-Film), are evaluated for the photodegradation of NO<sub>x</sub> under visible light. Compared to the benchmark material TiO<sub>2</sub>, TC-PVDF nanoparticles demonstrate outstanding performance, boasting a specific surface area of 60.93 m<sup>2</sup>/g and minimal toxic NO<sub>2</sub> byproducts, with concentration as low as 3.54 ppb, constituting only 0.46% during NO<sub>x</sub> remediation. These nanoparticles exhibit remarkable stability, with less than a 10% decrease in efficiency after cycles of visible light irradiation. Plasma treatment transforms TC-PVDF from superhydrophobic to hydrophilic, with a contact angle reduction from 124.7° to 0°. Notably, TC-PVDF shows substantial efficiency enhancements, reaching 84.04%. This study broadens insights into catalytic bag filters, providing practical implications for their use in NO<sub>x</sub> removal. It offers innovative solutions for air purification, addressing environmental challenges and advancing sustainable technologies.