Synergistic adsorption-photocatalytic degradation of Rhodamine B dye using a 3D-printed photoreactor with g-CN homojunction-based thermosets coating: response surface methodology and adsorption modelling

In present work, graphitic carbon nitride (g-CN) homojunction were synthesized to investigate the synergistic effect of photocatalysis and adsorption on Rhodamine B (RhB) dye degradation. The photodegradation (DE%) and adsorption (R%) were evaluated under the irradiation of two 50 W LED lights and in dark for 6 hours, respectively. A three-level Box-Behnken design (BBD) were employed to study the effects of initial dye concentrations (5 to 20 ppm), recirculation flow rates (1 to 3 mL/min), and the number of photoreactors (2 to 6) with total 15 sets of experiment. A quadratic regression was developed to predict DE% with an error of less than 5.5% relative to the experimental data. Additionally, ANOVA analysis showed that the number of photoreactors is the most influential parameter (p0.98) and the separation factor (RL) has indicated the adsorption process is favourable (RL=0.05). Additionally, the adsorption experimental data fit well with the pseudo-second-order kinetic model (R2>0.98). Overall, the development of homojunction photocatalyst has provided an innovative and alternative approach for water remediation