Tailored Citric Acid-Functionalized Carbon Nitride Homojunction-Immobilized Carboxymethyl Cellulose 3D Photocatalytic Hydrogels: A Multifaceted Approach toward Environmental Remediation

The facile development of highly efficient visible light active metal-free homojunction photocatalysts with phenomenal photoelectron migration is emerging as a prominent method for diverse energy and environmental remediation applications. Through an effective cross-linking technique, citric acid-functionalized g-C3N4 homojunction/carboxymethyl cellulose hydrogel beads (ICN/CMC beads) were prepared. The photocatalytic studies of ICN/CMC beads exhibited 87% tetracycline degradation in 40 min under visible light irradiation. The important advantages of ICN/CMC beads are their ease of recovery and reusability of up to 12 cycles. The ICN/CMC beads were capable of producing 2341 μmol of hydrogen peroxide and 501 μmol/h·g of ammonia production in 60 min under visible light irradiation. The predominant catalytic activity is due to the tuned bandgap of the photocatalyst, which facilitated the effective separation of electron–hole pairs and hindered the recombination of charge carriers. Thus, ICN/CMC beads are affordable and sustainable photocatalysts with multimodal applications.