Efficient hybrid capacitive deionization with MnO2/g-C3N4 heterostructure: Enhancing Mn dz2 electron occupancy by interfacial electron bridge for fast charge transfer

While MnO 2 has been identified as a potent agent in the desalination process , its efficacy is significantly impeded by its inherent poor electrical conductivity and substantial ion diffusion barriers . By orchestrating an interfacial electron bridge within the MnO 2 /g-C 3 N 4 heterostructure , reinforced through N p z -Mn d z 2 orbital hybridization, we have managed to significantly boost both SAC and SAR in the HCDI process. The reinforced N p z -Mn d z 2 orbital hybridization triggers a substantial electron transition from g-C 3 N 4 to MnO 2 , culminating in a high Mn d z 2 electron occupancy. Further analysis reveals the formation of a Mn N chemical bond at the MnO 2 /g-C 3 N 4 interface, operating as an essential electron transfer bridge from g-C 3 N 4 to MnO 2 . This process concurrently initiates a rise in the Mn d z 2 orbital energy level, equipping the Mn d z 2 electron with superior redox activity. With these enhancements, the manufactured MnO 2 /g-C 3 N 4 exhibits exemplary performance, boasting an improved SAC of 68 mg g −1 and SAR of 3.6 mg g −1  min −1 with a decreased energy consumption of 0.7224 kWh kg −1 at 1.2 V. This innovative work offers an unconventional roadmap for activating electron redox activity and thereby accelerating charge transfer in transition metal oxides .