Oxygen-incorporated carbon nitride porous nanosheets for highly efficient photoelectrocatalytic CO2 reduction to formate

Figure 1. Catalyst synthesis and structural characterization. (a) Schematic of the synthesis derived from melamine and urea. TEM images showed the morphology of CN1 (b) and CN2 (c) and CN3 (d) and CN4 (f), inset digital photograph show CN nanosheets solution, respectively. Figure 2. X-ray diffraction patterns (a) and FT-IR spectra (b) and EPR spectra (c) of CN simples, g (CN1) = 2.005; g (CN2) = 2.005; g (CN3) = 2.004; g (CN4) = 2.004. (d) steady-state photoluminescence (PL) spectra of CNs.Figure 3. Characterizations of catalytic functions of the CNs and photoelectrocatalysis performances of CNs toward CO2 reduction. (a) LSV curves of the CNs in the 0.5 M Na2SO4 aqueous solution. (b) Photocurrent−potential curves of the CNs under AM 1.5G illumination (c). Photocurrent-time curves of CNs at −0.9 V vs RHE with light on and off. (d) Photocurrent stability of the CN1 photoanode at 0.4 V versus RHE under AM 1.5G illuminatio.Figure 4. (a) AM 1.5G light induced electron/hole separation and transfer process during PEC CO2RR in CN photoanode.Figure. 5 (a) UV-visible DRS of CNs. Corresponding Tauc plots for CNs using (F(R)hν)1/2 (Kubelka–Munk parameter) as a function versus the photon energy (b). XPS survey spectrum, High-resolution N 1s XPS spectrum (c), O 1s XPS spectrum (d) of CNs.