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Photosynthesis of hydrogen peroxide (H2O2) is regarded as an economically efficient and environmentally friendly synthesis method. However, the scalability of photocatalytic H2O2 production (PHP) is hindered by the sluggish reaction kinetics and rapid recombination of photogenerated charge carriers. In this study, an organic amine‐constrained ions intercalated carbon nitride/CdSe‐diethylenetriamine (K+/I−‐CN/CdSe‐D) S‐scheme heterojunction is synthesized using an organic–inorganic hybrid approach and employed for PHP for the first time. The optimization of the heterojunction interface by I− and K+ ions contributed to enhanced light absorption capabilities and reduced interlayer charge transfer distance. Concurrently, the synergy of C─Se bonds at interface effectively modulated the electron transfer pathways. The coordination environment and charge transfer mechanism are thoroughly investigated by extended X‐ray absorption fine structure and in situ irradiated X‐ray photoelectron spectroscopy. The H2O2 production rate of 40%K+/I−‐CN/CdSe‐D reached 2240.23 µmol h−1 g−1 in pure water. This study highlights the significance of dual tuning of interface chemical bonds and ionic intercalation as an effective strategy for enhancing the photocatalytic H2O2 , paving the way for further advancements in PHP technology. [ABSTRACT FROM AUTHOR]

The S‐scheme heterojunctions have great potential for photocatalytic carbon dioxide reduction due to their unique carrier migration pathways, superior carrier separation efficiencies, and high redox capacities. However, the precise process of the oriented powerful electron transport remains a great challenge. Herein, an InOCd bond‐modulated S‐scheme heterojunction of In2O3/CdSe‐DETA is synthesized by a simple microwave‐assisted hydrothermal method for the accelerated photogenerated electron transfer. Meanwhile, the oxygen vacancies (Vo) of In2O3 have an electron capture effect. Consequently, thanks to the synergistic effect of this In‐Vo‐In‐O‐Cd structural units at the interface, electrons are extracted and rapidly transferred to the surface‐active sites, which improves the electronic coupling of CO2. This finding precisely adjusts the electron transfer pathway and shortens the electron transfer distance. The synergistic effect of this chemical bond established in the S‐scheme heterostructure with oxygen vacancies in In2O3 (Vo‐In2O3) provides new insights into photocatalytic CO2 reduction. [ABSTRACT FROM AUTHOR]

Step‐scheme (S‐scheme) heterojunctions have been extensively studied in photocatalytic carbon dioxide (CO2) reduction due to their excellent charge separation and high redox ability. The built‐in electric field at the interface of a S‐scheme heterojunction serves as the driving force for charge transfer, however, the poor interfacial contact greatly restricts the carrier migration rate. Herein, we synthesized the g‐C3N4/Bi19Br3S27 S‐scheme heterostructure through in situ deposition of Bi19Br3S27 (BBS) on porous g‐C3N4 (P‐CN) nanosheets. The C−S bonds formed at the interface help to enhance the built‐in electric field, thereby promoting the charge transfer and separation. As a result, the CO2 reduction reaction performance of 10 %Bi19Br3S27/g‐C3N4 (BBS/P‐CN) reaches 32.78 μmol g−1h−1, which is 341.4 and 18.7 times higher than that of pure BBS and P‐CN, respectively. X‐ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) prove the presence of chemical bonds (C−S) between the P‐CN and BBS. The S‐scheme charge‐transfer mechanism was analyzed via XPS and density functional theory (DFT) calculations. This work provides a new idea for designing heterojunction photocatalysts with interfacial chemical bonds to achieve high charge‐transfer and catalytic activity. [ABSTRACT FROM AUTHOR]

The design of a step‐scheme (S‐scheme) heterojunction can promote the separation of photogenerated carriers and optimize the oxidation–reduction capacity of the photocatalyst to the greatest possible extent. It is one of the most effective schemes for enhancing the efficiency of photocatalytic hydrogen production. In this work, an S‐scheme of Mn0.2Cd0.8S‐diethylenetriamine/porous g‐C3N4 (MCS/PCN) heterojunction is designed, which accelerates the charge transfer at the interface of Mn0.2Cd0.8S‐diethylenetriamine (Mn0.2Cd0.8S‐DETA) and porous g‐C3N4 (Pg‐C3N4), and provides electrons for photocatalytic hydrogen production. Under the same light conditions, the hydrogen production efficiency of the MCS/PCN composite is 11.42 mmol h‐1 g‐1, which is 30 times higher than that of pure Pg‐C3N4. By constructing this in situ grown S‐scheme heterojunction, a new direction for the precise design of charge separation is provided. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ultrathin InVO 4 /CdSe-amine nanocomposite is obtained. • The nanocomposite exhibited excellent photocatalytic CO 2 reduction and stability. • Mechanism of charge transfer and separation in S-scheme heterojunction is proposed. • S-scheme photocatalytic mechanism is discussed. The formation of interfacial chemical bonding in heterostructures plays an important role in the transport of carriers. Herein, we firstly prepared ultrathin InVO 4 nanosheet (Ns) with a thickness of 1.5 nm. Diethylenetriamine-modified CdSe (CdSe-DETA) nanobelts are in-situ deposited on the surface of ultrathin InVO 4 Ns to build a InVO 4 /CdSe-DETA step-scheme (S-scheme) heterojunction photocatalysts. The protonated DETA acts as an amine-bridge to promote the formation of a tight chemical bond at the interface of InVO 4 /CdSe-DETA, thereby promoting the transfer of carriers at the interface. For photocatalytic CO 2 reduction, the rationally designed InVO 4 /CdSe-DETA S-scheme photocatalyst exhibits a remarkable CO generation rate of 27.9 µmol h−1 g−1 at 420 nm, which is 3.35 and 3.39 times higher than that of CdSe-DETA and InVO 4 Ns, respectively. The new method by using interfacial chemical bonding to facilitate interfacial charge transportation provide a promising strategy for improve photocatalysis. [ABSTRACT FROM AUTHOR]

The article presents the discussion on utilisation of Solar energy which being the most important renewable energy on Earth. Topics include photocatalysis utilizing solar energy for decomposing water to produce hydrogen, reducing carbon dioxide for synthesizing solar fuel, and degrading pollutants to purify the environment; and intramolecular migration of electrons and hole leading to enhanced photocatalytic hydrogen evolution.

Solar‐driven carbon dioxide reduction is a promising strategy to manage the global carbon balance. Here, we built the Sn/Cd3(C3N3S3)2 (CdTMT) composite to achieve nearly 99% selectivity in the conversion of CO2 to CO. The Gibbs free energy reveals the lower activation energy barrier of CdTMT and Sn to the formation of the *OCHO intermediate. The metal Sn on the surface of CdTMT to form the Schottky heterojunction significantly improves the separation efficiency of photogenerated carriers, and the surface plasmon resonance of Sn can expand and enhance the visible light response range and absorption intensity, boosting the photocatalytic activity for CO2 reduction, which was about 3.7 times that of the pure CdTMT. Therefore, this study can provide new insights into the design and construction of metal–organic semiconductors to realize high‐selectivity heterojunctions in CO2 photoreduction conversion. [ABSTRACT FROM AUTHOR]

Photocatalytic CO2 reduction to value‐added fuels is an appealing avenue in response to global warming and the energy crisis, but it still suffers from high energy barriers, low conversion efficiencies, and poor photostability. Herein, a novel S‐scheme SnNb2O6/CdSe–diethylenetriamine (SNO/CdSe–DET) heterojunction is designed by a microwave‐assisted solvothermal process, composed of 2D ultrathin SNO nanosheets (NSs) and amine‐modified CdSe–DET nanorods (NRs). The SNO/CdSe–DET composite without any co‐catalyst possesses a boosted performance in the solar‐driven photocatalytic conversion of CO2 to CO, and the highest CO evolution rate achieved is 36.16 μmol g−1 h−1, which is roughly 3.58 and 9.39 times greater than those of CdSe–DET and SNO under visible‐light illumination. Such a superior activity should be ascribed to the S‐scheme system, which benefits the separation of the photogenerated carriers and promotes the synergy between CdSe–DET NRs and SNO NSs by strong chemical‐bonding coordination. Meanwhile, DET can enhance CO2 adsorption/activation and precisely regulate the surface reactive sites. This innovative work provides fresh insight into the development of highly efficient S‐scheme photocatalytic heterostructures for CO2 reduction. [ABSTRACT FROM AUTHOR]

Abstract Semiconductor heterojunction represents a family of promising photocatalysts for visible-light photocatalysis. In this work, a novel ternary g-C 3 N 4 /ZnS/SnS 2 heterostructure has been designed and synthesized by a facile one-step hydrothermal method. The obtained ternary g-C 3 N 4 /ZnS/SnS 2 heterostructures exhibited high photocatalytic activity in photodegradation of organic pollutants and photocurrent response irradiated by 410 nm LED light. The results demonstrated that the formation of the heterostructures can much improve the excellent photocatalytic activity if the lattice and energy level matching among the three semiconductors be satisfied, which causes efficient separation of photoinduced carriers, resulting in the high photodegradation of methylene blue (MB). As a result, the highest apparent rate constant K app of g-C 3 N 4 /ZnS/SnS 2 hybrid is 0.148 min−1, which is 8.74, 3.22 and 37.01 times as high as that of pristine g-C 3 N 4 , SnS 2 and ZnS, respectively. Graphical abstract Image 1 Highlights • g-C 3 N 4 /ZnS/SnS 2 composite is successfully synthesized by facile process. • The composite showed visible light activity for dye degradation. • The composite showed excellent photostability. • Charge carrier transfer pathways are proposed. [ABSTRACT FROM AUTHOR]

In this paper, a large scale and facile process was proposed for fabricating uniform and cheap Cu/Ag/Ag 3 PO 4 core–shell coaxial nanowires at room temperature. Cu/Ag/Ag 3 PO 4 ternary nanowire photocatalysts were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and ultraviolet–visible diffuse reflectance spectra (DRS). Photocatalytic tests displayed that the Cu/Ag/Ag 3 PO 4 heterostructures possessed a higher degradation rate of methylene blue than pure Ag 3 PO 4 and P25 under visible light irradiation. The enhanced photocatalytic performance could be attributed to effective separation of photogenerated carriers driven by photoinduced potential difference generated at the metal-semiconductor heterojunction interface. Repetitive tests showed that the Cu/Ag/Ag 3 PO 4 heterostructures maintained high stability over 5 cycles. This kind of cheap and high-efficient hybrid photocatalysts are expected to show considerable potential applications in pollution controlling. [ABSTRACT FROM AUTHOR]

It's important to reduce recombination of electrons and holes and enhance charge transfer through fine controlled interfacial structure. In this work, novel graphitic-C 3 N 4 (g-C 3 N 4 )/Ag 2 WO 4 /Ag ternary photocatalyst has been synthesized by deposition of Ag 2 WO 4 onto g-C 3 N 4 template and followed by sun light reduction of Ag 2 WO 4 into Ag 2 WO 4 /Ag. As-prepared g-C 3 N 4 /Ag 2 WO 4 /Ag presented significantly enhanced photocatalytic performance in degrading methylene blue (MB) under 410 nm LED light irradiation. Metallic Ag 0 is used as plasmonic hot spots to generate high energy charge carriers. Optimal g-C 3 N 4 content has been confirmed to be 40 wt%, corresponding to apparent pseudo-first-order rate constant kapp of 0.0298 min −1 , which is 3.3 times and 37.3 times more than that of pure g-C 3 N 4 and Ag 2 WO 4 , respectively. This novel ternary g-C 3 N 4 /Ag 2 WO 4 /Ag structure material is an ideal candidate in environmental treatment and purifying applications. [ABSTRACT FROM AUTHOR]

Highlights: [•] Facet coupled structure between F-TiO2-{001} and g-C3N4-{002} was prepared. [•] g-C3N4/F-TiO2 facet coupled hybrid has largely increased the area of heterojunction. [•] C3N4/TiO2 showed high photocatalytic activity with irradiation of LED light. [Copyright &y& Elsevier]

• Novel porous reduced graphite oxide/CdS-DETA composites were obtained. • The composites exhibited excellent photocatalytic H2 production and stability. • Photocatalytic mechanism is discussed. • DFT calculation further confirms the high mobility for charge transfer. Cadmium sulfide (CdS), as a promising candidate for photocatalytic hydrogen evolution (PHE), has been widely studied in recent years. However, the PHE performance of CdS is largely limited by the severe photocorrosion and low quantum efficiency. Herein, we reported multi-walled carbon nanotubes (MWCNTs) exfoliated porous reduced graphene oxide (PRGO)-supported inorganic-organic CdS-diethylenetriamine (DETA) hybrid, and the system is designed and prepared to adjust electronic structure and control photocorrosion property. Irradiated by visible light (λ > 400 nm), this novel PRGO/CdS-DETA system exhibits advanced PHE performance of 10.5 mmol g−1 h−1 and apparent quantum efficiency is 29.5% with enhanced photostability. This result is 13.1, 3.9, 1.5 and 1.3 times higher than CdS nanoparticles, CdS-DETA hybrids, MWCNT/CdS-DETA and RGO/CdS-DETA composites. More importantly, the special connection between PRGO and CdS-DETA facilitates the charge carriers separation and large BET specific surface area (S BET) boost the PHE of CdS-DETA. Density functional theory (DFT) calculation further confirms the high mobility for charge transport route from CdS-DETA to PRGO. The PRGO/CdS-DETA system photocatalyst with high PHE performance may provide a new insight into photocatalytic material design. [ABSTRACT FROM AUTHOR]

• Bi 2 S 3 /Pg-C 3 N 4 heterostructure is successfully prepared. • Bi 2 S 3 /Pg-C 3 N 4 heterostructure shows high photocatalytic activity. • Step-scheme photocatalytic mechanism is proposed. The band engineering is an efficient route to utilize solar energy to solve environment pollution with the help of visible-light-driven photocatalysts. In this work, two different narrow band gap semiconductors, porous g-C 3 N 4 (Pg-C 3 N 4) and Bi 2 S 3 , were prepared by one-pot method to form the step-scheme Bi 2 S 3 /Pg-C 3 N 4 heterostructure photocatalyst. The crystal phase, morphology and optical properties of as-prepared samples were measured by X-ray diffraction (XRD), transmission electron microscopy (TEM), UV–Vis DRS spectra. Bi 2 S 3 /Pg-C 3 N 4 heterostructure exhibits excellent photocatalytic activity under visible light, which is much better than that of pure Bi 2 S 3 and Pg-C 3 N 4. The constant k app of Bi 2 S 3 /Pg-C 3 N 4 heterostructure is 0.01993 min−1, which is 16.33 and 29.74 times greater than that of pure Pg-C 3 N 4 and Bi 2 S 3 , respectively. In addition, the photocatalytic degradation efficiency of Bi 2 S 3 /Pg-C 3 N 4 heterostructure can remain 80.2% after three cycles. Finally, a step-scheme photocatalytic mechanism of Bi 2 S 3 /Pg-C 3 N 4 was proposed. [ABSTRACT FROM AUTHOR]

In the present work, a series of Ag2O/KNbO3 composite photocatalysts are prepared for the first time through an in situ growth method. The as-obtained samples are well characterized by X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, UV-vis absorption spectroscopy, and X-ray photoelectron spectroscopy. The photocatalytic properties of the samples are assessed by decomposition of rhodamine B (RhB) under visible-light excitation. The results demonstrate Ag2O/KNbO3 illustrated superior photocatalytic activity. The rate constant of RhB degradation over the optimal sample (Ag2O/KNbO3-6:1) exceeded 2.78 and 65 times higher than that of pure Ag2O and KNbO3, respectively. The improved photocatalytic activity could be due to the heterostructure of the catalyst, which enhance the visible light absorption capacity and the separation efficiency of photogenerated carriers. The quenching experiments of varied scavengers illustrated that •O2− and h+ were the primary active species in the decoloration of RhB. [ABSTRACT FROM AUTHOR]

In recent years, converting solar energy into chemical energy has been shown to be a promising method to alleviate the problem of a global energy shortage. Coupling different semiconductors to construct a step-scheme (S-scheme) heterojunction photocatalyst has become one of the most effective methods. Through the amination of CdS, a 2D/2D BiOBr/CdS-diethylenetriamine (B/CS-D) S-scheme heterojunction was constructed to achieve efficient charge carrier separation and transfer. It is worth noting that the optimal B/CS-D photocatalyst, with the BiOBr mass ratio of 40%, shows a CO production rate of 19.4 μmol h−1g−1, which is 3.68 times higher than that of CdS-D. The rate of 40%B/CS without D is 11.2 μmol h−1g−1, and the catalyst becomes severely corroded, however, by constructing an S-scheme heterojunction containing D, the stability of the photocatalyst can be improved due to the existence of amine molecules which strengthen the interface contact, and the 2D structure, which increases the area of the contact, thereby speeding up the separation and transmission of carriers. This study shows the construction of an S-scheme heterostructure photocatalyst with improved separation of photoexcited holes and electrons, and a retardation of the corrosion of CdS. [ABSTRACT FROM AUTHOR]

Construction of high-stability heterojunctions for two-dimensional composites with enhanced photocatalytic performance is regarded as a promising approach to treat wastewater. Herein, the novel direct Z-scheme Zn 3 V 2 O 8 /Ag 3 PO 4 heterostructured photocatalyst was rationally fabricated via a simple two-step solution method, demonstrating importantly enhanced activity of methylene blue (MB) under visible light irradiation. Particularly, the degradation rate constant (k app) of 20%Zn 3 V 2 O 8 /Ag 3 PO 4 heterojunction is as high as 0.0715 min−1, which is 1.55 and 35.76 times higher than that of pristine Ag 3 PO 4 and Zn 3 V 2 O 8 , respectively. Additionally, 20%Zn 3 V 2 O 8 /Ag 3 PO 4 composite has excellent stability and its degradation efficiency can still maintain about 90% after four cycles. Based on the reasonable characterizations and analyses for the heterostructure, the enhanced photocatalytic property and excellent stability can be ascribe to the formation of a novel direct Z-scheme heterojunction between Zn 3 V 2 O 8 and Ag 3 PO 4 , which presents high-efficient charge carriers separation, improved redox capacity and excellent visible light absorption. This work offers a new strategy to design the direct Z-scheme heterojunction photocatalyst in the degradation. Image 1 • Zn 3 V 2 O 8 /Ag 3 PO 4 composite was successfully prepared. • The composite showed high visible light photocatalytic activity. • The composite showed excellent photostability. • Z-scheme photocatalytic mechanism is proposed. [ABSTRACT FROM AUTHOR]

Rapid recombination of photoexcited carriers has always been a severe problem that inhibits photocatalytic activity. Designing two-dimensional (2D) heterostructured nanocomposite using layer material is regarded as an effective method to obtain advanced photocatalyst. In this work, we designed novel 2D/2D porous graphitic C 3 N 4 /SnS 2 (Pg-C 3 N 4 /SnS 2) composite by in-situ growth of SnS 2 onto Pg-C 3 N 4 sheets. The 2D Pg-C 3 N 4 nanosheets were coupled with 2D SnS 2 nanosheets forming a large-scale contact interface, leading to high efficient interfacial charge transfer efficiency and shortening the distance of charge transmission. According to the experiments, the optimized Pg-C 3 N 4 /SnS 2 composite exhibits the highest apparent pseudo-first-order rate constant k app of 0.14321 min−1 with the content of 10%Pg-C 3 N 4 , which exceeds the rates of pure Pg-C 3 N 4 and SnS 2 for approximately 18 and 8 times, respectively. On the basis of radical-trapping experiment and band structure analysis, we confirm that the Z -scheme heterojunction was formed between SnS 2 and Pg-C 3 N 4. The electrons in SnS 2 CB transfer and combine with the holes in the Pg-C 3 N 4 , which is beneficial to the spatial separation of photoinduced carriers and strengthen the redox capacity of the photocatalyst. This work supplies an efficient way to design 2D/2D heterojunction for the photocatalytic application. Unlabelled Image • 2D/2D Pg-C 3 N 4 /SnS 2 composite was successfully prepared. • The composite showed high visible light photocatalytic activity. • The composite showed excellent photostability. • Z-scheme photocatalytic mechanism is proposed. [ABSTRACT FROM AUTHOR]

Inadequate photogenerated carriers' separation is deemed to be the major obstacles for improving photocatalytic H 2 evolution. Here, we designed distinctive Ni 2 P/porous g-C 3 N 4 /Cd 0.5 Zn 0.5 Se-diethylenetriamine (Ni 2 P/pg-C 3 N 4 /Cd 0.5 Zn 0.5 Se-D) nanojunction via an in-situ solvothermal synthesis. The cooperative effect of Cd 0.5 Zn 0.5 Se-D and Ni 2 P can extend the visible light absorption for pg-C 3 N 4. As a result, the ternary Ni 2 P/pg-C 3 N 4 /Cd 0.5 Zn 0.5 Se-D composite exhibits high-performance H 2 evolution rate of 12627 μmol g−1 h−1 using solar light, being almost 105.23 and 2.59 folds higher than those observed over Ni 2 P/pg-C 3 N 4 and pg-C 3 N 4 /Cd 0.5 Zn 0.5 Se-D composite, severally. The possible mechanism is assumed that the formation of the novel Ni 2 P modified step-scheme (S-scheme) pg-C 3 N 4 /Cd 0.5 Zn 0.5 Se-D heterojunction which manipulated highly efficient spatial separation and directional migration of photocarriers. Moreover, DFT calculations have been performed to uncover the process of the charge transport. This work concentrates on the profound part of noble-metal-free decorated S-scheme photocatalytic system in water splitting. [ABSTRACT FROM AUTHOR]

Heterostructured photocatalysts are promising candidates in the photocatalysis field, and the heterojunction plays a vital role in the separation of spatial charge carriers. Here, a heterojunction was fabricated by the in situ growth of ultrathin Bi 12 O 17 Cl 2 (BOC) nanosheets (NSs) onto porous g-C 3 N 4 (PGCN) NSs. The NSs' nanostructure can effectively shorten the diffusion path of charge carriers and thus promote interfacial charge migration, which can improve the surface photocatalytic activity. The X-ray photoelectron spectroscopy spectra and the experimental measured Fermi level (E F) indicate that electrons transfer from PGCN to BOC, which leads to the formation of the built-in electric field with the orientation from PGCN to BOC. Driven by the built-in electric field, the charge carriers transfer through a step-like pathway. This step-scheme porous g-C 3 N 4 /Bi 12 O 17 Cl 2 (PGCN/BOC) heterostructured nanocomposite displays an enhanced photocatalytic performance compared with pure BOC and PGCN. This work provides new insight into the novel construction of a step-scheme heterojunction toward photocatalytic CO 2 reduction. [ABSTRACT FROM AUTHOR]

At present, photocatalytic technology for degradation of organic matter is a promising water treatment technology. Two-dimensional (2D) nanomaterials are getting more and more attention based on unique physical and chemical properties. In this work, 2D SnNb 2 O 6 nanosheets were prepared by hydrothermal method, and then Ag 3 VO 4 was loaded on the surface of SnNb 2 O 6 nanosheets by chemical deposition to form a compact and stable step-scheme (S-scheme) heterostructure. S-scheme system not only efficiently separated the charge carriers spatially, but also retained the electrons with higher reduction ability and holes with higher oxidation ability. Therefore, the novel SnNb 2 O 6 /Ag 3 VO 4 S-scheme heterojunction shows the best photocatalytic activity, which is much better than pristine SnNb 2 O 6 and Ag 3 VO 4. The constant K app of SnNb 2 O 6 /Ag 3 VO 4 heterojunction is calculated to be 0.2256 min−1, which is 16.2 and 1.6 folds higher than that of the pristine SnNb 2 O 6 (0.0139 min−1) and Ag 3 VO 4 (0.1395 min−1), respectively. Moreover, the SnNb 2 O 6 /Ag 3 VO 4 heterojunction maintains good photostability in 3 cycles. [ABSTRACT FROM AUTHOR]

Inorganic-organic hybrid nanomaterials, with excellent chemical and physical properties and technology applications, have attracted much attention in many fields. In the photocatalytic field, it is still a problem to find a stable, adjustable morphology and band gap and effective photocatalyst in utilizing solar energy conversion to hydrogen (H 2) to solve the energy crisis. Herein, with the assistance of diethylenetriamine (DETA), the novel inorganic-organic CdSe-DETA hybrids with different morphology and adjustable band gap have been synthesised via simple microwave hydrothermal method. The morphological transformation mechanism involves the consumption of organic components controlled by the mixed precursor and subsequent self-assembly of residual inorganic components (CdSe). Under the visible light irradiation (λ > 420 nm), CdSe-18DETA nanobelt, showed the best photocatalytic H 2 production activity (5.75 mmol·g−1·h−1), which is 3.03 times greater than that of pure CdSe (1.90 mmol·g−1·h−1). Moreover, after four cycles, the photocatalytic H 2 production activity can still remain 91.27% of initial value, which indicates its good photocatalytic stability. Our results provide a promising approach for designing visible-light photocatalysts with efficient electron-hole separation and adjustable morphology and band gap. [ABSTRACT FROM AUTHOR]

Abstract Constructing direct Z-scheme heterojunction photocatalysts is a highly efficient pathway to completely utilize the high redox ability of photogenerated charge carriers. Herein, a direct Z-scheme porous g-C 3 N 4 (Pg-C 3 N 4)/BiOI heterojunction was constructed through the in-situ growth of BiOI on the surface of Pg-C 3 N 4. First principle density functional theory calculations indicated that charge transfer would occur from Pg-C 3 N 4 to BiOI due to the difference in their Fermi energies, resulting in a strong internal electric field (IEF) at the interface between Pg-C 3 N 4 and BiOI. Under photoexcitation, the electrons in the conduction band (CB) of BiOI combine with the holes in the valance band (VB) of Pg-C 3 N 4 with the help of IEF at the interface. A possible Z-scheme type charge transfer can be achieved. This special charge transfer mechanism greatly improved the separation efficiency of photogenerated charge carriers and maintained the high redox ability of photogenerated electrons in the CB of Pg-C 3 N 4 and photogenerated holes in the VB of BiOI. Photocatalytic activities were estimated by the photodegradation of methylene blue under visible light. Results indicated that Pg-C 3 N 4 /BiOI exhibited higher photocatalytic performance than pure Pg-C 3 N 4 and BiOI, which can be attributed to the Z-scheme type charge transfer between Pg-C 3 N 4 and BiOI. This work provides new insights into the high photocatalytic activities of g C 3 N 4 based heterojunction photocatalysts. Graphical abstract Image 1 Highlights • Novel porous g-C 3 N 4 /BiOI composite photocatalyst were prepared. • The composites exhibited excellent photodegradation of MB activity and stability. • Direct Z-scheme photocatalytic mechanism used to explain activity enhancement. • DFT calculation further confirms the presence of Direct Z-scheme mechanism. [ABSTRACT FROM AUTHOR]

Abstract: By employing the perovskite-structured stannates and manganites, p-La0.67Ca0.33MnO3/i-SrSnO3/n-La0.03Sr0.97SnO3 junctions were fabricated on SrTiO3(001) substrates by pulsed laser deposition technique. The current–voltage curves indicate an excellent rectifying property of the heterojunction in the measurement temperatures from 310 to 10K. A crossover from negative to positive of magnetoresistance with bias voltage was observed, which was explained by the transport mechanism of diffused electrons. [Copyright &y& Elsevier]

To keep excellent redox ability and facilitate the separation of charge carriers, step-scheme (S-scheme) photocatalytic systems have been used in the photocatalytic H 2 production. Recently, all kinds of photocatalysts with excellent performance and stability have been formed. Especially, 2D/2D heterojunction materials have attracted tremendous attention for the faster interfacial charge separation and transfer between them and much active centers. In this work, we designed a series of heterostructure photocatalysts of 2D/2D porous graphitic C 3 N 4 (Pg-C 3 N 4)/CdS-diethylenetriamine (DETA) nanocomposites and explored the S-scheme mechanism via density functional theory (DFT) calculations and XPS analysis. Under visible light irradiation, the experimental results indicated that the designed nanocomposites of water splitting photocatalytic activity for hydrogen evolution was 9738 μmol h−1 g−1, which is 1.7 and 12.2 times higher than that of CdS-DETA and Pg-C 3 N 4. The performance improvement is mainly due to the following reasons: 1) Pg-C 3 N 4 with large specific surface area could provide more active sites; 2) 2D/2D heterojunction have the faster interfacial charge separation and transfer rate; 3) DETA could synergistically promote the improvement of performance. This work not only introduces a novel Pg-C 3 N 4 /CdS-DETA heterojunction but also provides an approach on designing 2D/2D heterojunction for application in photocatalysis. ga1 • Pg-C 3 N 4 /CdS-DETA system was prepared. • Pg-C 3 N 4 /CdS-DETA system exhibited excellent photocatalytic H 2 production. • Pg-C 3 N 4 /CdS-DETA system is stable during the photocatalytic reaction. • S-scheme photocatalytic mechanism is proposed. [ABSTRACT FROM AUTHOR]

• CoO/PCN heterostructure is successfully prepared. • CoO/PCN heterostructure shows high photocatalytic CO 2 reduction. • S-scheme charge transfer mechanism observed between CoO and PCN. The construction of heterojunction plays a key role in solving the charge separation and transfer at the interface of photocatalyst. Herein, a new type of step-scheme (S-scheme) heterojunction was formed by growing cobalt oxide (CoO) in situ on porous graphitic carbon nitride (PCN) to convert CO 2 to CO. The porous structure of PCN can increase the absorption of CO 2 and act as an active site. The special charge separation of S-scheme heterojunction can give CoO/PCN system with strong redox ability. And S-scheme heterojunction can accelerate charge separation and transfer at the interface. Compared with CoO and PCN, CoO/PCN composites exhibits a higher CO 2 reduction rate (40.31 μmol g-1h−1), 3.43 and 23.85 times higher than that of CoO (11.73 μmol g-1h−1) and PCN (1.69 μmol g-1h−1), respectively. [ABSTRACT FROM AUTHOR]