TMP/Pd Complex Immobilized on Graphene Oxide for Efficient Pseudocapacitive Energy Storage with Combined Experimental and DFT Study

Designing sophisticated energy sources that can offer a large amount of electricity for various energy storage uses is a pressing need. In this study, Trimethoprim (TMP) was functionalized as a rich supply of nitrogen and oxygen on graphene oxide (FGO-TMP), using graphene oxide layers adorned with trimethoprim functional groups. Then, using a simple approach to synthesize FGO-TMP/Pd complex for supercapacitor applications, palladium ions were reacted and fixed on the FGO-TMP composite surface. The FGO-TMP/Pd composite produced was characterized as a symmetric capacitor with a capacitance of 330F/g at 5 mV s−1 and high energy and power densities of 60.3 W h Kg−1 and 1200 W kg−1, respectively. After 10,000 cycles at 8 A/g, this symmetric device retained 93.7 percent of its original capacitance, proving the remarkable capacitive performance of the developed platform as well as ultra-stability for such sophisticated energy storage devices. Topological analysis of the electron density distribution and its Laplacian at the bonding critical points and Bader atomic charges of the GO layer in both FGO-TMP and FGO-TMP/Pd composites confirms more concentrated bond charges in FGO-TMP/Pd, indicating effective improvement in electrode material behavior in a supercapacitor.