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Enhancing charge separation in semiconductor photocatalysts is a major challenge for efficient artificial photosynthesis. Herein, a compact heterojunction is designed by embedding half‐metallic C(CN)3 (hm‐CN) hydrothermally in BiOBr (BOB) as the backbone. The interface between hm‐CN and BOB is seamless and formed by covalent bonding to facilitate the transmission of photoinduced electrons from BOB to hm‐CN. The transient photocurrents and electrochemical impedance spectra reveal that the modified composite catalyst exhibits a larger electron transfer rate. The photocatalytic activity of hm‐CN/BOB increases significantly as indicated by a CO yield that is about four times higher than that of individual components. Density‐functional theory calculations verify that the heterojunction improves electron transport and decreases the reaction energy barrier, thus promoting the overall photocatalytic CO2 conversion efficiency. The half‐metal nitride coupled semiconductor heterojunctions might have large potential in artificial photosynthesis and related applications. [ABSTRACT FROM AUTHOR]

By embedding Na ions into graphitic carbon nitride, the directional migration of photo-generated electrons towards Na sites is achieved, thereby creating additional reaction sites. Moreover, the electron-rich Na sites enhance the adsorption and activation of CO 2. Consequently, the photocatalytic performance is improved to some extent. [Display omitted] The depressed directional separation of photogenerated carriers and weak CO 2 adsorption/activation activity are the main factors hampering the development of artificial photosynthesis. Herein, Na ions are embedded in graphitic carbon nitride (g-C 3 N 4) to achieve directional migration of the photogenerated electrons to Na sites, while the electron-rich Na sites enhance CO 2 adsorption and activation. Na/g-C 3 N 4 (NaCN) shows improved photocatalytic reduction activity of CO 2 to CO and CH 4 , and under simulated sunlight irradiation, the CO yield of NaCN synthesized by embedding Na at 550°C (NaCN-550) is 371.2 μmol g−1 h−1, which is 58.9 times more than that of the monomer g-C 3 N 4. By means of theoretical calculations and experiments including in situ fourier transform infrared spectroscopy, the mechanism is investigated. This strategy which improves carrier separation and reduces the energy barrier at the same time is important to the development of artificial photosynthesis. [ABSTRACT FROM AUTHOR]

A S-Scheme heterojunction with close contact between CN and CoTPP was establish by a unique synthesis method. Formation of S-type heterojunction facilitated the efficient separation of photogenerated carriers and improved photocatalytic activity. [Display omitted] • The g-C 3 N 4 is rapidly synthesized by the technology of thermal polycondensation. • Co-porphyrins is introduced to increase the catalytic activity of the catalyst. • Adjusting the ratio of loads can regulate the activity of CO 2 reduction. • S-scheme heterojunction promotes efficient separation of photogenerated carriers. The emissions of CO 2 are increasing year by year, which have led to serious environmental problems. Converting CO 2 into valuable fuels through photocatalysis is a promising strategy. In this research, oxygen atoms were successfully innovated into graphitic carbon nitride (CN). Additionally, cobalt porphyrin (CoTPP) was successfully loaded onto the modified carbon nitride (Co/CN). The generation of interfacial electric fields and bending bands between CN and CoTPP was demonstrated experimentally. The electrons in the CN and the holes in the CoTPP were combined to form a unique S-scheme heterojunction structure, and efficient separation of carriers was promoted. As a result, the CO conversion under visible light irradiation reached an impressive 100.70 μmol g−1 h−1. By integrating theoretical and experimental findings, this study underscores the critical role of catalyst design in enabling efficient photocatalytic CO 2 reduction. [ABSTRACT FROM AUTHOR]