3D porous carbon nitride composited oxygen vacancy‐induced indium oxide for high photocatalytic nitrogen fixation on the interfacial surface

Semiconductor photocatalysis can utilize solar energy for clean energy conversion, but the catalytic efficiency is often unsatisfactory due to limited photo response and efficient separation of photogenerated carriers. In this work, 3D porous carbon nitride (3DPCN) composited oxygen vacancy‐induced indium oxide (3DPCN/V O ‐In 2 O 3 ) was successfully prepared and analyzed by some characterization methods. Meanwhile, the performance of photocatalytic nitrogen fixation was further investigated. X‐ray photoelectron spectroscopy and X‐Ray diffraction (XRD) confirmed the successful preparation of the composites and revealed the electron flow direction; scanning electron microscopy (SEM) and transmission electron microscopy showed the surface structure of the composites; diffuse reflectance spectroscopy and temperature programmed desorption (TPD) revealed the energy band position and adsorption mechanism; electron paramagnetic resonance (EPR) characterization confirms the successful construction of oxygen vacancies; and electrochemical impedance spectroscopy, photoluminescence, and other photochemical characterization results showed that 3DPCN/V O ‐In 2 O 3 band gap is narrower and more effective in capturing light than other materials, improving the photocatalytic nitrogen fixation ability. The test results show that the nitrogen fixation capacity of 3DPCN/V O ‐In 2 O 3 can reach a maximum value of 156 within 2 h. This result demonstrates that the modification of carbon nitride improves its nitrogen fixation effect, and the introduction of oxygen vacancy‐induced In 2 O 3 improves the light absorption performance and is advantageous to the separation of photogenerated charge carriers.