3D-printed photoreactor with robust g-C₃N₄ homojunction based thermoset coating as a new and sustainable approach for photocatalytic wastewater treatment

Recently, the rapid technological advancement in photocatalysis has gained popularity as a means of addressing climate change and environmental degradation issues. The rapid surge in interest for 3D-printing process has delivered solutions for a broad spectrum of needs primarily due to its flexibility, cost effectiveness and environmental friendliness. In addition, the development in synergizing photocatalysis and 3D-printing technology has provided an optimistic outlook for sustainable wastewater treatment. In present study, a 3D-printed photocatalytic reactor was successfully designed and constructed via digital light processing technique. Besides that, a visible-light sensitive photocatalyst, graphitic carbon nitride homojunction was synthesized via a facile hydrothermal approach. The as-developed photocatalyst was then prepared in a form of thermoset coating and subsequently applied onto the base of 3D-printed photoreactor. A series of characterization tests were conducted to gain an in-depth understanding of the surface morphology and topology, chemical structure, thermal stability, elemental compositions, and surface wettability of the photocatalyst system. The photocatalytic performance of the graphitic carbon nitride homojunction-based thermoset coating was evaluated via Rhodamine B (RhB) dye degradation under the irradiation of a 50 W LED light. A removal efficiency of 95.62% was achieved within 24 h with a corresponding kinetic rate constant of 2.1 × 10⁻³ min⁻¹. The recyclability of the photocatalytic system was verified by assessing its photoactivity for five consecutive cycles and retained 98.5% of its initial photoactivity. Overall, this research work may intrigue more exploration between interdisciplinary researchers in the field of photocatalysis and additive manufacturing, especially for sustainable environmental remediation.