1：Experimental Design and Method Selection:

The study uses a one-pot scalable chemical precipitation method to synthesize CNC-rGO hybrid material, characterized by FESEM, XRD, and XPS. Electrochemical measurements include CV, GCD, and EIS for supercapacitor evaluation, and voltammetric and amperometric techniques for H2O2 sensing.

2：Sample Selection and Data Sources:

Samples include synthesized CNC, CNC-rGO, and their composites with chitosan. Data are obtained from laboratory experiments using standard electrochemical cells.

3：List of Experimental Equipment and Materials:

Equipment includes FESEM, XRD (Bruker D8 focus), XPS, electrochemical workstation (CHI Instruments, 660E), glassy carbon electrode, Ag/AgCl reference electrode, Pt counter electrode. Materials include CuCl2·2H2O, NaOH, L-Ascorbic acid, graphene oxide, chitosan, sodium sulphate, PBS, H2O

4：Experimental Procedures and Operational Workflow:

Synthesis involves mixing GO with CuCl2·2H2O, adding NaOH and AA, stirring, centrifugation, and drying. Electrode preparation includes drop-casting suspensions on GCE. Measurements are conducted in three-electrode cells with specific electrolytes and potential windows.

5：Data Analysis Methods:

Specific capacitance calculated from GCD curves using equation Csp = (I * dt) / (m * dV). Sensitivity and detection limits determined from amperometric responses. EIS data fitted to Randles circuit.