An EPR analysis was conducted to analyze the radical formation and stability of the CPB NCs and CPB/ZIF-8 composite. This experiment used the 5-tert-butoxycarbonyl-5-methyl-1pyrroline-n-oxide (BMPO) as the spin trap. Interestingly, the CPB and CPB/ZIF-8 composite were photoactive and showed strong EPR signals (Figure ). This indicates that both materials can generate charge carriers (electrons and holes) when exposed to light. The CPB/ZIF-8 composite exhibited a stronger EPR signal than pristine CPB NCs. This enhancement suggests a higher concentration of unpaired electrons or radicals in the composite system. The increased radical formation in the composite can be attributed to several factors. One is improved charge separation; the ZIF-8 framework may facilitate better separation of photogenerated electrons and holes, reducing their recombination rate and allowing more charges to participate in radical formation. That assumption is also supported by the PL results presented above. Another factor might be the enhanced stability; the higher stability of CPB NCs within the ZIF-8 framework allows for prolonged photoactivity and sustained radical formation. The EPR signals detected in both CPB and CPB/ZIF-8 composite exhibited a distinct quartet peak, indicating the presence of hydroxyl radicals (•OH). To confirm the formation of the •OH, DMSO was added to the samples as a quencher, and EPR signals were analyzed. After adding the DMSO, the EPR signals were quenched, confirming the formation of •OH during the process. The EPR measurements are carried out in the dark and under illumination (Tungsten lamp) conditions in the 10% (v/v) EtOH/Toluene solution (Figure ). The ZIF-8 was found to be EPR inactive, and it is due to the presence of solely Zn 2+ ions in its crystal structure. The EPR analysis reveals that the CPB/ZIF-8 composite exhibits enhanced stability and superior radical formation capabilities, particularly in generating •OH. This stability and increased radical formation efficiency can make the CPB/ZIF-8 composite a promising material for various photocatalytic applications, potentially outperforming pristine CPB NCs in effectiveness and durability. (10% (v/v) EtOH/toluene) conditions used for EPR analysis were also maintained for the dye degradation studies. The characteristic peaks at 421 nm for MO and 610 nm for BCG were used to monitor dye degradation. BCG also showed an additional peak at 412 nm, attributed to its monoanionic form and the pH dependency of the solution. . Both dyes were stable under illumination and dark conditions without a catalyst (Figures and). All dye degradation results indicated that the CPB/ZIF-8 nanocomposite exhibited superior photocatalytic activity compared to CPB NCs and ZIF-8. Specifically, CPB/ZIF-8 achieved 1.48 and 1.75 times higher degradation efficiency than CPB NCs within 30 minutes for MO and BCG dye, respectively (Figure and S17a). The CPB/ZIF-8 composites demonstrated a significant 1.5-times improvement in activity compared to previously reported CPB/MOF composites in the degradation of MO. The degradation kinetics studies also revealed that both CPB/ZIF-8 and CPB NCs have good linear coefficients, indicating that they follow pseudo-first-order kinetics for both dyes (Figures and). The calculated parameters, such as the apparent rate constant, quantum efficiency (QE), and electrical energy consumption (EEC), were superior in the CPB/ZIF-8 nanocomposites. All the results regarding the photocatalysis are summarized in Table , with a detailed discussion included in the supplementary information. The superior performance of the CPB/ZIF-8 nanocomposite can be attributed to the synergistic effect between CPB and ZIF-8, which enhances stability, increases •OH formation, and improves overall catalytic efficiency. This makes the CPB/ZIF-8 nanocomposite a promising material for environmental remediation applications, particularly in degrading organic dye pollutants.