We investigated the CO2 adsorption and electrochemical conversion behavior of triazole-based C3N5 nanorods as a single matrix for consecutive CO2 capture and conversion. The pore size, basicity, and binding energy were tailored to identify critical factors for consecutive CO2 capture and conversion over carbon nitrides. Temperature-programmed desorption (TPD) analysis of CO2 demonstrates that triazole-based C3N5 shows higher basicity and stronger CO2 binding energy than g-C3N4. Triazole-based C3N5 nanorods with 6.1 nm mesopore channels exhibit better CO2 adsorption than nanorods with 3.5 and 5.4 nm mesopore channels. C3N5 nanorods with wider mesopore channels are effective in increasing the current density as an electrocatalyst during the CO2 reduction reaction. Triazole-based C3N5 nanorods with tailored pore sizes exhibit CO2 adsorption abilities of 5.6–9.1 mmol/g at 0 °C and 30 bar. Their Faraday efficiencies for reducing CO2 to CO are 14–38% at a potential of −0.8 V vs. RHE.
Bibliographical noteFunding Information:
This work was financially supported by the Australian Research Council (ARC) (grant numbers DE170101069, FT100100970, and IH180100020) and the National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIT) (grant number 2021R1C1C1008941). NEXAFS measurements were performed on the Soft X‐ray beamline at Australian Synchrotron with the support of the Australian Nuclear Science and Technology Organisation (grant number AS172/SXR/1285). R.D. acknowledges funding from the UNSW Digital Grid Futures Institute, UNSW Sydney, under a cross disciplinary fund scheme.
© 2021 Wiley-VCH GmbH
- carbon nitrides
- CO capture
- CO reduction
- porous materials