Robust graphitic carbon nitrite-based thermoset coating for synergistic adsorption–photocatalysis process in 3D-printed photoreactors

With the rapid advances in photocatalytic nanomaterials and 3D printing technology, the present work involves the incorporation of these two technologies for a green wastewater treatment. At the preliminary stage, a visible-light-sensitive photocatalyst, graphitic carbon nitride (g-C₃N₄) homojunction, was synthesized via facile hydrothermal approach. Additionally, the photocatalytic reactors were then constructed via digital light processing (DLP) technique. Four (4) comprehensive 3D-printed photoreactors coated with metal-free g-C₃N₄ homojunction semiconductor were assembled and arranged in series for degradation of Rhodamine B (RhB). The surface morphology of 3D printed reactor with g-C₃N₄ based thermoset coating was analyzed using field emission scanning electron microscopy (FESEM). The photocatalytic system successfully removed 93.46 % of RhB via adsorption and photocatalysis within 8 h under the irradiation of two 50 W LED lights. The photoreactors also exhibited excellent recyclability with negligible drop in its photocatalytic efficiency after three continuous experimental runs. The mechanism for RhB photodegradation underlying g-C₃N₄ homojunction was also proposed based on scavenging tests. In essence, the experimental outcome may elicit more interdisciplinary research interest between photocatalysis and 3D printing in addressing current global environmental issues.