Copper nanoparticles decorated N-doped mesoporous carbon with bimodal pores for selective gas separation and energy storage applications

• Mesoporous N & Cu doped carbon materials with enhanced physico-chemical features. • Materials display redox, conducting, basic, adsorption and porous characteristics. • N/Cu doped carons show ordered structure with a bimodal pores size distribution. • High gas adsorption capacity and selectivity in a mixture of CO 2 /H 2 and CO 2 /CH 4. • High values for supercapacitance with good cyclic ability and capacitance retention. We demonstrate a synthesis of copper nanoparticles decorated over nitrogen-doped mesoporous carbon with different N and Cu contents which exhibit conducting, redox, basic, adsorption, and excellent textural properties. These materials are prepared through a nanotemplating approach by simultaneously encapsulating sucrose, guanidine hydrochloride, and Cu(NO 3 ) 2 into the porous channels of mesoporous SBA-15 at a low carbonization temperature of 600 °C. The prepared materials exhibit an ordered mesoporous carbon framework with bimodal pores, decorated with nitrogen and Cu functionalities on the surface of the pores and in the wall structure. The presence of nitrogen functionalities in the porous carbon matrix not only helps to reduce the Cu ions but also stabilizes the nanoparticles and offers redox sites, which are beneficial for adsorption and electrochemical applications. The optimized sample exhibits the highest adsorption capacity of different gases such as CO 2 – 22.5 mmol/g at 273 K, H 2 −13.5 mmol/g at 77 K at 30 bar and CH 4 − 5 mmol/g at 298 K and 50 bar. We also demonstrate that the prepared material shows a high selectivity of adsorption towards CO 2 in a mixture of CO 2 /H 2 and CO 2 /CH 4 and it also registers a high supercapacitance of 209 F g −1 at a current density of 1 A g −1 with excellent cyclic stability.