Direct utilization of air and water as feedstocks in the photo-driven nitrogen reduction reaction over a ternary Z-scheme SiW₉Co₃/PDA/BWO hetero-junction

Abstract

Sustainable solar-to-ammonia conversion under ambient conditions using air and water as feedstock is a promising approach to supply low-concentrated ammonia (fertilizer) for farms. In the present work, the semiconductor-like polyoxometalate,...

A minireview on catalysts for photocatalytic N2 fixation to synthesize ammonia

“…Z scheme is a special case of heterojunctions. Z schemes AgBr/Bi 4 O 5 Br 2 , 79 Bi 2 O 3 @CoAl-LDHs, 80 3,4-dihydroxybenzaldehyde-functionalized Ga 2 O 3 /g-C 3 N 4 , 81 g-C 3 N 4 /Mg 1.1 Al 0.3 Fe 0.2 O 1.7 , 82 nano-MOF@defected g-C 3 N 4 (MOF: metal organic frameworks) 83 and SiW 9 Co 3 /PDA/BWO (PDA: poly-dopamine; BWO: Bi 2 WO 6 ) 84 have been reported active in PNF. In these Z schemes, the separation of photoinduced electron–hole pairs was significantly improved, which played a dispensable role in boosting their catalytic activities.…”

Photocatalytic nitrogen reduction to ammonia: Insights into the role of defect engineering in photocatalysts

“…Formation of a heterostructure can extend spectral range of light absorption, and also induce a built-in electric field to facilitate the separation and migration of electron-hole pairs, favoring photocatalysis [320]. Integration of defect engineering and heterostructuring can present a strong synergistic effect to drastically enhance the N2 photoreduction [321].…”

Designing “Core–Shell” Insoluble‐SiW11Fe@δ‐Bi2O3 Z‐Scheme Heterojunction for Photo‐Driven Nitrogen Reduction Reaction and Evaluating the Impact of Oxygen toward Nitrogen Reduction

“…The binding energies of 159.1 (Bi4f 7/2 ) and 164.5 eV (Bi4f 5/2 ) with 5.4 eV difference confirm the oxidation state of +3 for Bi in pure δ-Bi 2 O 3 . [56] The emergence of sub-peaks with binding energies of 157.9 (Bi4f 7/2 ) and 163.3 eV (Bi4f 5/2 ) strongly indicates the presence of OVs, which render the apparent oxidation state of +(3−x) [41,[57][58][59] (note: binding energy for metallic Bi(0) locates at 156.93 eV for Bi4f 7/2 ). [60] After forming composites, the binding energies for Bi 3+ reduced by 0.3 eV in Cs 5 SiW 11 Fe@δ-Bi 2 O 3 , and 0.4 eV in Ru 2.5 SiW 11 Fe@δ-Bi 2 O 3 .…”

“…[34,35] Then, semiconductor-like poly oxometalates (POMs) are widely employed to construct heterojunction, owing to their merits of reversible redox featured with multi-electron transfer and extended light absorption adjusted by transition metal substitutions. [36][37][38] In photo-driven process, certain POMs derived catalysts have been developed for nitrogen fixation in water using nitrogen or air as feedstocks, such as HV-C 3 N 4 /r-PW 12 , [39] Ag/PW 12 /Zr-mTiO 2 , [40] SiW 9 Co 3 / PDA/BWO, [41] and SiW 12 /K-C 3 N 4 . [42] From a practical viewpoint, air would be better feedstock in comparison with pure nitrogen, yet NH 3 /NH 4 + production reduces under air atmosphere.…”