Search

Introducing piezoelectric materials with the built-in electric field caused by mechanical force has been confirmed as an effective strategy to boost the separation efficiency of photoexcited charge carriers that determines the photocatalytic performance. In this study, we introduced Bi4Ti3O12 with superior piezoelectric properties into BiVO4–Bi4V2O10 materials to synthesize a 2D Bi4Ti3O12–BiVO4–Bi4V2O10 photocatalyst via a facile hydrothermal method. Compared with bare BiVO4, the Bi4Ti3O12–BiVO4–Bi4V2O10 piezo-photocatalytic activity towards Cr(VI) removal and oxygen evolution is boosted remarkably under both illumination and ultrasound treatments. The promoted photocatalytic activity can be ascribed to the accelerated photoexcited carrier separation efficiency driven by the polarization electric field and the synergy effect in the heterostructure. This work provides a simple and sustainable strategy for the design and development of piezo-photocatalysts with high photoredox activity capacity. [ABSTRACT FROM AUTHOR]

[Display omitted] • A dual p-n heterojunction composed of NiCo 2 O 4 /NiO/Al: SrTiO 3 was fabricated. • The dual p-n heterojunction was constructed with electrostatic adsorption force. • MOF-derived NiCo 2 O 4 /NiO was used as the O 2 -producing co-catalyst for water splitting. • The property of dual p-n heterojunction is superior to the single p-n heterojunction. • The built-in electric field contributes to the enhanced photocatalytic performance. In this study, NiCo 2 O 4 /NiO/Al: SrTiO 3 (labeled as NCO/NO/ASTO) with dual p-n heterojunction structure was devised and in-situ fabricated for the first time, in which metal–organic framework (MOF)-derived NiCo 2 O 4 /NiO (NCO/NO) was utilized as the O 2 -producing co-catalyst. This dual p-n heterojunction with the matching built-in electric field made it possible to separate and transfer charge carriers in a manner that was substantially more effective than the use of a single p-n heterojunction. The NCO/NO/ASTO-1 exhibits an excellent overall water splitting performance of 1.74 (H 2)/0.85 (O 2) mmol g−1h−1 when exposed to UV radiation, which is 1.3 and 2.6 times that of NiCo 2 O 4 /Al: SrTiO 3 (NCO/ASTO) and NiO/Al: SrTiO 3 (NO/ASTO) with single p-n heterojunction structure, respectively. The electrostatic adsorption force and matching built-in electric field between ASTO and NCO/NO have been demonstrated, ensuring the presence as well as the stability of the dual p-n junction and accelerating the migration of photogenerated carriers. Moreover, density functional theory (DFT) was used to offer theoretical evidence of the driving force for the interfacial charge transfer in the NCO/NO/ASTO dual p-n heterojunction, which could be attributed to the difference in the work functions (Φ) of the components of NO, NCO, and ASTO. [ABSTRACT FROM AUTHOR]

As a visible-light photocatalyst, bismuth iodide oxide (BiOI) is widely applied in water photocatalytic pollution degradation. However, due to the inherent high recombination rate of electron−hole pairs, an efficient photocatalytic performance could realize rarely by bare BiOI, resulting in its limited practical application. In this study, a novel type-II BiOI−C 3 N 5 heterostructure was prepared by a feasible solvothermal method to inhibit the recombination of photoexcited electrons and holes. The photocatalytic activity of the heterostructure was evaluated by degradation of tetracycline (TC) and penicillin G sodium. The results showed that compared with bare C 3 N 5 and BiOI, the photodegradation efficiency of tetracycline and penicillin G sodium was remarkable improved after heterostructure formation and the BiOI−C 3 N 5 (10% wt) samples demonstrated a higher degradation efficiency. The improvement of photocatalytic degradation activities can be attributed to the formation of type-II heterostructures with a close contact. Under the synergistic effect and interface structure in BiOI−C 3 N 5 , the spatial separation and transfer of charge carriers were increased significantly, which is in favor of enhancing the photocatalytic oxidation capacity of BiOI. [Display omitted] • A new BiOI-C 3 N 5 heterostructure was successfully constructed to heighten the photocatalytic oxidation capacity of BiOI. • Synergistic effect and interfacial fusions in BiOI −C 3 N 5 were formed for accelerating the charge carriers transfer. • The BiOI−C 3 N 5 heterostructures exhibit remarkable tetracycline (TC) and sodium penicillin G degradation performances. [ABSTRACT FROM AUTHOR]

Herein, we report a one-dimensional (1D) S-doped K3Ti5NbO14@TiO2 (STNT) core-shell heterostructured composite with an enhanced photocatalytic degradation activity under visible light, which was prepared by a simple reassembly-calcination method using thiourea as the S source. The anisotropically shaped rods are favorable for the rapid transport of photogenerated charge carriers. The substitution of Ti4+ by S6+ is primarily incorporated into the lattice of the TiO2 shell so as to create an intra-band-gap state below the conduction band (CB) position, giving rise to Ti−O−S bonds and thus the visible light response. The presence of electron-deficient S atoms is of benefit to the decreased recombination rate of photogenerated electrons and holes by capturing electrons (e−). Meanwhile, a tight close interface between K3Ti5NbO14 and TiO2 was formed to achieve a nano-heterojunction structure, leading to the fostered separation of its interfacial photogenerated electrons and holes. The visible-light-driven photocatalytic degradation of methylene blue (MB) by STNT composites is higher than that by pure K3Ti5NbO14, owing to the synergistic effects of S doping and heterojunction. A possible photocatalytic mechanism was proposed with a reasonable discussion. This work may provide an insight into constructing highly efficient core-shell photocatalysts used toward sustainable environmental remediation and resource shortages. [ABSTRACT FROM AUTHOR]