Unraveling the unique role of brown graphitic carbon nitride in robust CO2 photoreduction

Stacking Engineering of Heterojunctions in Half‐Metallic Carbon Nitride for Efficient CO2 Photoreduction

“…After exposing to light for a certain period of time, the peaks at 1,653, 1,358, and 1,097 cm −1 corresponding to the intermediates of CO 2 − , b‐CO 3 2− , and *CHO, respectively, increase. [ 50,51 ] As the irradiation time goes up, the intensity of the intermediates also increases, suggesting strong electron transfer between BOB and hm‐CN and promoted charge separation and absorption of the intermediate *COOH. Consequently, the reactions for photocatalytic reduction are proposed as shown in the following: $$$$\begin{equation}{\mathrm{CO}}_{\mathrm{2}} + {\mathrm{*}} \to {\mathrm{*C}}{{\mathrm{O}}}_{\mathrm{2}}\end{equation}$$$$ $$$$\begin{equation}{\mathrm{*C}}{{\mathrm{O}}}_{\mathrm{2}} + {\mathrm{H}}^{\mathrm{ + }} + {\mathrm{e}}^{\mathrm{ - }} \to {\mathrm{*COOH}}\end{equation}$$$$ $$$$\begin{equation}{\mathrm{*COOH}} + {{\mathrm{H}}}^{\mathrm{ + }} + {{\mathrm{e}}}^ - \to {\mathrm{*CO}} + {{\mathrm{H}}}_{\mathrm{2}}{\mathrm{O}}\end{equation}$$$$ $$$$\begin{equation}{\mathrm{*CO}} \to {\mathrm{CO}} \uparrow + {\mathrm{*}}\end{equation}$$$$ $$$$\begin{equation}{\rm{*C}}{{\rm{H}}}_{\rm{2}}{\rm{O}} + {{\rm{H}}}^{{ + }} + {{\rm{e}}}^ - \to {\rm{*C}}{{\rm{H}}}_{\rm{3}}{\rm{O}}\end{equation}$$$$ …”

“…After exposing to light for a certain period of time, the peaks at 1,653, 1,358, and 1,097 cm −1 corresponding to the intermediates of CO 2 − , b‐CO 3 2− , and *CHO, respectively, increase. [ 50 , 51 ] As the irradiation time goes up, the intensity of the intermediates also increases, suggesting strong electron transfer between BOB and hm‐CN and promoted charge separation and absorption of the intermediate *COOH. Consequently, the reactions for photocatalytic reduction are proposed as shown in the following: …”

Organic polymer facilitated CO2 photoreduction: a minireview

“…In addition, Liu et al also prepared oxygen-linked g-C 3 N 4 using glycolic acid and urea as precursors. 68 The oxygen-linked introduction is able to provide more electrons for participating in the process of CO 2 activation and photoreduction, resulting in CH 4 as the largest among all the products, which is different from CO as the dominating product over bulk g-C 3 N 4 . It was proved that the presence of the oxygen-linked structure can effectively suppress the recombination of photogenerated electrons and holes, thus leading to different rate-limiting steps and product selectivity.…”