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Combining the strong localized surface plasmon resonance (LSPR) of metallic Ag and the chemically reactive Pt co-catalyst, the Ag–Pt bimetallic composite was prepared and then coated on the surface of the exfoliated defective graphitic carbon nitride nanosheets (C 3 N x NS) for plasmon hot electron-mediated photocatalytic H 2 evolution. Under the visible light irradiation, the sample of (1:2) Ag–Pt/C 3 N x NS exhibits the highest activity (1.25 mmol g−1 h−1), which is 35.7 and 1.7 times higher than that of Ag/C 3 N x NS and Pt/C 3 N x NS, respectively. Moreover, the apparent quantum efficiency (AQE) of (1:2) Ag–Pt/C 3 N x NS reaches 3.3% at 420 nm. The boosted photocatalytic capacity may be ascribed to the utilization of the advantages of the LSPR effect of Ag particles and the Schottky barrier between Pt and C 3 N x NS, resulting in more electrons participate in the reduction reaction to boost the photocatalytic H 2 evolution performance. [Display omitted] • Ag–Pt core-shell structure was deposited on the exfoliated defective C 3 N x nanosheets. • The Core Ag shows LSPR effect and the shell Pt acts chemically reactive co-catalyst. • The (1:2) Ag–Pt/C 3 N x NS exhibits the highest H 2 evolution rate (1.25 mmol g−1 h−1). • The AQE of the sample of (1:2) Ag–Pt/C 3 N x NS reaches 3.3% at 420 nm. • The boosted activity was attributed to the LSPR effect and the Schottky barrier. [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]

[Display omitted] • [Mo 3 S 13 ]2− nanoclusters are highly dispersed into the micropores of TpPa-1-COF. • The size and micro-environment of micropores play a central role in anchoring MS-c. • The photocatalytic H 2 evolution rate of MS-c@TpPa-1 is increased by 4.7 times. • The coordinated Mo − N groups between MS-c and TpPa-1-COF result in enhanced stability. • The favorable electron–proton transfer to form H* occurs on the S instead of N sites. Non-noble-metal-based [Mo 3 S 13 ]2− nanoclusters (MS-c) as a co-catalyst face the problems of instability and inevitable aggregation, which limit its photocatalytic applications. Herein, β-ketoenamine-linked covalent organic framework (COF), namely TpPa-1-COF, was utilized to embed MS-c. The micropores of TpPa-1-COF could not only limit the growth of MS-c to achieve its high dispersion but also play a central role in anchoring MS-c. Moreover, the structural stability of MS-c is highly enhanced due to the confinement effect of TpPa-1-COF, and the visible-light-driven photocatalytic H 2 evolution rate of 528 μmol g−1h−1 for MS-c@TpPa-1 (0.3: 1), which is increased by 4.7 times as compared with that of TpPa-1-COF. The density functional theory (DFT) calculations indicate that the electrons transfer from TpPa-1 to MS-c occurs at the interface of MS-c@TpPa-1 in the ground state based on the charge density difference analysis. With the irradiation of visible light, the photoexcited electrons derived from the π-conjugated TpPa-1-COF backbone could be delivered to the embedding MS-c through the coordinated Mo − N groups, and the favorable electron–proton transfer to form H* and efficient desorption of H 2 occurs on the S sites instead of N sites in MS-c@TpPa-1, resulting in the enhanced photocatalytic H 2 evolution rate. Overall, this work provides a novel approach for embedding the unstable MS-c with low cost into the micropores of COF via coordination bonds to improve the structural stability and photocatalytic activity. [ABSTRACT FROM AUTHOR]

[Display omitted] • [Mo 3 S 13 ]2− nanoclusters are highly dispersed into the micropores of TpPa-1-COF. • The size and micro-environment of micropores play a central role in anchoring MS-c. • The photocatalytic H 2 evolution rate of MS-c@TpPa-1 is increased by 4.7 times. • The coordinated Mo − N groups between MS-c and TpPa-1-COF result in enhanced stability. • The favorable electron–proton transfer to form H* occurs on the S instead of N sites. Non-noble-metal-based [Mo 3 S 13 ]2− nanoclusters (MS-c) as a co-catalyst face the problems of instability and inevitable aggregation, which limit its photocatalytic applications. Herein, β-ketoenamine-linked covalent organic framework (COF), namely TpPa-1-COF, was utilized to embed MS-c. The micropores of TpPa-1-COF could not only limit the growth of MS-c to achieve its high dispersion but also play a central role in anchoring MS-c. Moreover, the structural stability of MS-c is highly enhanced due to the confinement effect of TpPa-1-COF, and the visible-light-driven photocatalytic H 2 evolution rate of 528 μmol g−1h−1 for MS-c@TpPa-1 (0.3: 1), which is increased by 4.7 times as compared with that of TpPa-1-COF. The density functional theory (DFT) calculations indicate that the electrons transfer from TpPa-1 to MS-c occurs at the interface of MS-c@TpPa-1 in the ground state based on the charge density difference analysis. With the irradiation of visible light, the photoexcited electrons derived from the π-conjugated TpPa-1-COF backbone could be delivered to the embedding MS-c through the coordinated Mo − N groups, and the favorable electron–proton transfer to form H* and efficient desorption of H 2 occurs on the S sites instead of N sites in MS-c@TpPa-1, resulting in the enhanced photocatalytic H 2 evolution rate. Overall, this work provides a novel approach for embedding the unstable MS-c with low cost into the micropores of COF via coordination bonds to improve the structural stability and photocatalytic activity. [ABSTRACT FROM AUTHOR]