1：Experimental Design and Method Selection:

The study involved the reduction and functionalization of graphene oxide (GO) using 2,4-diamino benzene sulfonic acid (2,4-DBSA) under reflux conditions. The process was designed to simultaneously reduce GO and functionalize it with sulfonated aromatic diamine groups.

2：Sample Selection and Data Sources:

GO was synthesized from graphite powder using the modified Staudenmaier method. The reduction/functionalization process was applied to GO to produce rGO2,4-DBSA.

3：List of Experimental Equipment and Materials:

Equipment included a Branson 3800 bath sonicator, D-500 Siemens diffractometer, Perkin Elmer Spectrum GX and Bruker Tensor 27 FT-IR spectrometers, SPECS GmbH XPS instrument, SETARAM SETSYS Evolution 18 Analyser for TGA, Autosorb-1-MP for nitrogen adsorption/desorption isotherms, Renishaw in-Via Reflex spectrometer for Raman spectroscopy, JEOL-JEM 2100 TEM, and JEOL JSM-6510LV SEM. Materials included graphite powder, 2,4-diamino benzene sulfonic acid, sulfuric acid, nitric acid, potassium chlorate, and various solvents.

4：Experimental Procedures and Operational Workflow:

GO was synthesized, then reduced and functionalized with 2,4-DBSA under reflux. The product was characterized using various spectroscopic and microscopic techniques. Conductive inks were prepared from rGO2,4-DBSA and printed on flexible substrates using gravure printing.

5：Data Analysis Methods:

Data from XRD, FT-IR, XPS, TGA, Raman spectroscopy, and electrical measurements were analyzed to confirm the reduction and functionalization of GO, and to evaluate the properties of the resulting rGO derivatives.