Photo-Catalysis: A Clear Path to Cleaner Chemistry

Photocatalysis is a fast-advancing pillar of green chemistry with strong promise for sustainable, energy-efficient environmental remediation. Drawing on studies from ۲۰۱۸–۲۰۲۴, this review surveys progress, challenges, and future directions in semiconductor photocatalysts—emphasizing titanium dioxide (TiO₂) and its modified forms alongside g-C₃N₄ composites and high-entropy oxides—which are valued for low energy demand, operational simplicity, and effective degradation of persistent organic pollutants. Recent design strategies—metal/non-metal doping, heterojunction engineering, and composite construction—have expanded visible-light response, improved light harvesting, and suppressed charge recombination, yielding degradation efficiencies of ~۹۴–۹۶% for model dyes such as methylene blue and methyl orange and delivering ~۱۵–۲۵% gains in quantum efficiency versus conventional systems. Key practical barriers remain, including carrier recombination, photostability over long use, and limits in solar utilization, but converging advances in material architecture and reactor engineering are steadily translating lab performance into scalable, eco-friendly, and cost-effective technologies for industrial wastewater treatment and sustainable chemical manufacturing—pointing to a clear path toward cleaner chemistry.

Keywords:

Photocatalysis , Semiconductor photocatalysts , Visible-light activation , Environmental remediation , Catalyst design , Reactive oxygen species (ROS) , Sustainable materials , Wastewater Treatment