Unique Tubular BiOBr/g‐C₃N₄ Heterojunction with Efficient Separation of Charge Carriers for Photocatalytic Nitrogen Fixation

Abstract

The industrial ammonia synthesis process consumes a lot of energy and causes serious environmental pollution. As a sustainable approach for ammonia synthesis, photocatalytic nitrogen reduction employing water as the reducing agent has a lot of potential. A simple surfactant‐assisted solvothermal method is used to synthesize g‐C3N4 nanotubes with flower‐like spherical BiOBr grown inside and outside (BiOBr/g‐C3N4, BC). The hollow tubular structure realizes the full use of visible light by the multi‐scattering effect of light. Large surface areas and more active sites for N2 adsorption and activation are present in the distinctive spatially dispersed hierarchical structures. Particularly, the quick separation and transfer of electrons and holes are facilitated by the sandwich tubular heterojunctions and tight contact interface of BiOBr and g‐C3N4. The maximal NH3 generation rate of the BiOBr/g‐C3N4 composite catalysts can reach 255.04 μmol⋅ g−1⋅ h−1, and it is 13.9 and 5.8 times that of pure BiOBr and g‐C3N4. This work provides a novel method for designing and constructing unique heterojunctions for efficient photocatalytic nitrogen fixation.

Fluorinated-TiO2/Mn0.2Cd0.8S S-Scheme Heterojunction with Rich Sulfur Vacancies for Photocatalytic Hydrogen Production

“…It is commonly recognized that the efficiency of semiconductor photocatalysis is greatly influenced by the separation and transport of photogenerated carriers. , A series of photoelectrochemical characterization tests were performed on F-TiO 2 , MCS, and F-TiO 2 /MCS catalysts to examine their photogenerated charge separation and transfer behaviors. Figure a displays the transient photocurrent response of F-TiO 2 , MCS, and F-TiO 2 /MCS.…”

Applications of BiOX in the Photocatalytic Reactions

“…Xue et al reported that the photocatalytic nitrogen fixation performance of BiOBr was improved about 10 times by the synergistic effect of oxygen vacancy and ultra-thin layer structure [84]. Gao et al loaded the flower-like BiOBr onto the inner and outer sides of the C3N4 nanotubes simultaneously, effectively realizing the separation of photogenerated electrons and hole pairs, and thus increasing the photocatalytic nitrogen fixation activity of BiOBr by 13.9 times [85]. Now, photocatalytic nitrogen fixation capacities of BiOX are still unlikely to replace the Haber-Bosch process, but their potentials are huge and need In fact, pure BiOX exhibited low performance of photocatalytic nitrogen fixation.…”

Defect Engineering in Bi‐Based Photo/Electrocatalysts for Nitrogen Reduction to Ammonia

“…[27] Based on the above advantages, Bi-based materials are considered to be a promising candidate for photocatalytic NRR. The Bi-based NRR catalysts currently studied are of a wide variety, including metal Bi, [28,29] BiO 2-x , [30] Bi 2 S 3 , [31] BiOX (X=F, Cl, Br and I), [32][33][34] BiVO 4 , [35] (BiO) 2 CO 3 [36] and pentavalent bismuthate M(BiO 3 ) n (n = 1, M=Li, Na, K, Ag; n = 2, M=Mg, Zn, Sr, Ba, Pb) . [37,38] Zhang et al [39] synthesized Bi nanosheets by electrochemical reduction method as NRR electrocatalyst, which showed a high Faraday efficiency of 10.46 � 1.45 % at À 0.8 V (RHE).…”