Enhanced Charge Separation and Transfer of Fe₂O₃@Nitrogen‐Rich Carbon Nitride Tubes for Photocatalytic Water Splitting

Abstract

Carbon nitride is widely used in photocatalytic hydrogen production, but it is still difficult to split water without any sacrificial reagent. Herein, nanosized Fe2O3 is combined with 3D nitrogen‐rich carbon nitride tubes (ACN), to form an Fe2O3@ACN Z‐scheme heterojunction, which accelerates the electrons’ transfer from Fe2O3 to ACN and improves the charge separation efficiency. Meanwhile, the bandgap of Fe2O3@ACN is about 2.01 eV, beneficial to the enhancement of visible light absorption capacity. As a result, without any sacrificial agent, the hydrogen evolution rate reaches 3.7 μmol h−1 (10 mg catalyst, AM1.5) through water splitting, which is three times that of ACN and 45 times that of bulk C3N4 (GCN). This work provides a new strategy to prompt pure water splitting based on carbon nitride catalysts.

Enhanced Photocatalytic Activity by Pt Confined within N-Doped Carbon on TiO2 Inner Surface

“…The hollow nanostructure as shown in TEM and HAADF-STEM images (Figure ) could not only expose more active sites, but also increase light capture by light-scattering and slow photon effects and shorten the charge-transport distance to inhibit recombination of photogeneration carriers . In addition, NC@TiO 2 -900-HS shows a slightly higher H 2 generation rate than the pure TiO 2 -HS (Figure S4), indicating that the inner NC layer also plays a certain co-catalytic role on the photocatalytic property of TiO 2 due to the improved separation of carrier and the increased reactant adsorption as depicted in the literature. − …”

Advances in photo-assisted seawater splitting promoted by green iron oxide-carbon nitride photoelectrocatalysts

“…6, charge transfer across Fe 2 O 3 / gCN interfaces occurs due to a staggered type-II heterojunction mechanism, 13 at variance with literature reports on a-Fe 2 O 3 / gCN photocatalysts, for which a Z-scheme junction has been reported. [2][3][4][17][18][19]42,[47][48][49][51][52][53][54]58,60,64 As can be observed in Fig. 6, upon irradiation, valence-to-conduction band electron excitation occurs.…”

“…Molecular hydrogen (H 2 ) is expected to play an important role in driving mankind on the road to carbon neutrality, a foremost challenge to achieve ''net-zero emissions'' by 2050. [1][2][3][4][5][6][7][8][9][10][11] Differently from H 2 produced from fossil fuels ('grey hydrogen'), in conict with the achievement of these objectives, 'green hydrogen' obtained by electrochemical water splitting, possibly activated by sunlight, is environmentally friendly and renewable, and has gained remarkable interest to solve the global energy crisis and shape a sustainable energy economy. 1,[12][13][14][15][16][17][18][19] Nonetheless, the water splitting efficiency is limited by the kinetic barrier of the anodic oxygen evolution reaction (OER), possessing a high overpotential (h).…”

“…1,10,22,28,39,40 In this regard, it is worth highlighting that, if OER is carried out in alkaline solutions at an overpotential <0.48 V, ClO − generation from chloride oxidation can be favourably suppressed. 1,20,39,41 In the broad scenario of OER photoelectrocatalysts, hematite (a-Fe 2 O 3 ), the most stable iron(III) oxide polymorph, 4,15,16,23,42 is one of the most promising platforms due to its natural abundance, biocompatibility, low cost, good stability, and band gap (E G z 2.1 eV) enabling the absorption of a large solar spectrum portion. 2,6,12,16,23,43,44 These advantages are partially eclipsed by its small exciton diffusion length (z2-4 nm), as well as by the poor mobility and low lifetime of photogenerated charge carriers (<10 ps), restricting its practical applications.…”

Size Effect of (CuO)n (n = 1–6) Clusters on the Modification of Rutile–TiO2 Photocatalysts

“…Among the applications of cluster-sized catalysts, photocatalysis for hydrogen production, as a state-of-the-art approach for solar energy harvesting and utilization, has received extensive attention. [8][9][10][11] One particular research topic is the modification of titanium dioxide (TiO 2 ), which has been applied in many photocatalytic scenarios due to its favorable positions of band edge, chemical stability, nontoxicity, and low cost. [12][13][14][15][16][17][18] However, the photocatalytic efficiency of TiO 2 is limited by its inherent high charge recombination rate and weak photoabsorption ability in the visible range.…”