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Efficient light absorption and photoinduced electron transfer from the g-C 3 N 4 (CN) continue to be an ongoing challenge in photocatalytic hydrogen production. Nanodimensional metallic cocatalysts can offer superior electron transport pathways, thereby augmenting photocatalytic activity. In our work metallic NiCo 2 O 4 (NCO) acts as an electron acceptor cocatalyst in a 2D-2D Schottky junction with CN and 0D silver (Ag) functions as a hot electron donor via the localized surface plasmon resonance phenomenon. The novel Ag–CN–NCO nanocomposite was shown to boost visible light absorption while inhibiting charge carrier recombination through optical experiments. The Ag–CN–NCO nanocomposite demonstrated superior photocatalytic activity compared to CN loaded with a single cocatalyst, producing hydrogen at a rate of approximately 2320 μmol/g/h. Additionally, Ag–CN–NCO produced a lower overpotential and almost five times more photocurrent density than CN, as demonstrated by photoelectrochemical studies. This work highlights the development of a novel charge transfer pathway by combining two co-catalysts with different functions and their combined action on the photocatalytic hydrogen production process. [Display omitted] • 0D Ag as an electron donor cocatalyst via LSPR effect. • 2D metallic NiCo 2 O 4 as an electron donor cocatalyst via Schottky junction. • Investigation of unique interfacial charge transfer pathway. • Synergistic effects of Schottky junction and LSPR as dual strategies. • Hydrogen production rate of 2320 μmol/g/h. [ABSTRACT FROM AUTHOR]

Emerging tribovoltaic nanogenerator (TVNG) technology, which can capture mechanical energy at dynamic semiconductor interfaces and generate instant direct current (DC) outputs, is considered promising to mitigate growing energy demand. However, the unsatisfactory charge excitation and extraction efficiency limit its electrical output stability and even practicability. Here, a novel strategy is proposed to synergistically modulate charge generation and transfer dynamics by integrating ferroelectric and photovoltaic effect with tribovoltaic effect, and thus a multi‐effect coupled Schottky TVNGs is, for the first time, developed. Research indicates that such coupling mechanism involving ferroelectric polarization, photoexcitation, and triboelectricity can allow TVNGs to jointly collect light and mechanical energy to excite more charges, and meanwhile, incorporation of strong electric fields can also be induced by controlled polarization to assist Schottky junction in modulating separation/extraction efficiencies of these charges. Ultimately, this multi‐effect coupled devices deliver impressive DC output of 7.3 V and 69.8 µA, outperforming similar coupled Schottky junction TVNGs. Besides that, its feasibility for multifunctional sensing and photodetection is also demonstrated. This study proposes an effective strategy for modulating performance while extending its functionality, which can expedite the development and potential application of advanced TVNGs. [ABSTRACT FROM AUTHOR]

The prodigious employment of fossil fuels to conquer the global energy demand is becoming a dreadful threat to the human society. This predicament is appealing for a potent photocatalyst that can generate alternate energy sources via solar to chemical energy conversion. With this interest, we have fabricated a ternary heterostructure of Ti3C2 nanosheet modified g‐C3N4/Bi2O3 (MCNRBO) Z‐scheme photocatalyst through self‐assembly process. The morphological analysis clearly evidenced the close interfacial interaction between g‐C3N4 nanorod, Bi2O3 and Ti3C2 nanosheets. The oxygen vacancy created on Bi2O3 surface, as suggested by XPS and EPR analysis, supported the Z‐scheme heterojunction formation between g‐C3N4 nanorod and Bi2O3 nanosheets. The collaborative effect of Z‐scheme and Schottky junction significantly reduced charge transfer resistance promoting separation efficiency of excitons as indicated from PL and EIS analysis. The potential of MCNRBO towards photocatalytic application was investigated by H2O2 and H2 evolution reaction. A superior photocatalytic H2O2 and H2 production rate for MCNRBO is observed, which are respectively around 5 and 18 folds higher as compared to pristine CNR nanorod. The present work encourages for the development of a noble, eco‐benign and immensely efficient dual heterojunction based photocatalyst, which can acts as saviour of human society from energy crisis. [ABSTRACT FROM AUTHOR]

For the transformation of energy conversion and photocatalytic decomposition, photocatalyst-based artificial photosynthesis for solar-to green fuels and environmental treatment has aroused great attention. Herein, a novel ternary heterojunction based on constructing an interaction between 2D-graphitic carbon nitride (CN), 3D-strontium titanate (STO) and Pt nanoparticles (NPs) (2D/3D CN/STO@Pt) is designed for the first time to greatly promote photocatalytic water cracking hydrogen (H 2) evolution in an alkalescent environment, such as triethanolamine (TEO) as well as integrating with Rhodamin B (RhB) decomposition. Under optimized conditions, the H 2 productivity over 3D/2D CN/STO@Pt-3 heterostructures (10,005 μmol h−1 g−1) with an apparent quantum yield of H 2 production approaching 47.5% is found to be ∼29.7, 8.5, 1.1, and 1.5-fold as much as that in the CN, CN/STO, CN/STO@Pt-1, and CN/STO@Pt-5 heterojunctions, respectively. An up to 2.5-fold enhancement in the photocatalytic RhB decomposition rate, obtaining 90% within 60 min under visible-light-driven is observed for 3D/2D CN/STO@Pt-3 heterostructures, surpassing that of other samples. The CN/STO@Pt-3 sample shows the highest degradation rate of 3.5 min−1, which is 1.8, 2.8, 4.27 and 4.9 -time higher than that of the CN/STO@Pt-1, CN/STO@Pt-5, CN, and STO samples, respectively. The improved photocatalytic behavior of the heterogeneous structures could be ascribed to i) the type II-heterojunction between 2D CN and 3D STO; and ii) the creation of the Schottky contacts between semiconductors and Pt NPs. The configuration of the type-II heterojunction formed by the two semiconductors of 2D g-C 3 N 4 and 3D STO contributes to improved light absorption ability, and rapid separation and transfer of photoinduced charges. At the same time, the close junction of Pt establishes the Schottky barrier to facilitate efficient electron transfer in the ternary nanostructures, impeding the quick recombination of photoexcited charge carriers, and offering abundant reactive sites, contributing multiple electron pathways for the photoreaction strategy. Increased photocurrent density from the LSV measurement and a declined in PL intensity confirmed the enhanced interfacial charge separation in the tertiary photocatalyst. Furthermore, the CN/STO@Pt-3 ternary heterostructure presents outstanding photocatalytic performance after five cycles, indicating good stability and reusability. This work gives a valuable modification pathway for the establishing multi-channel charge carrier transport for energy conversion and environmental remediation processes. The diagram showing the photocatalytic activity of CN/STO@Pt heterostructures. [Display omitted] • The novel type II-Schottky structures of CN/STO@Pt were synthesized. • The RhB decomposition obtained 90% within 60 min under visible-light-driven. • The photocatalytic H 2 evolution rates reached 10,005 μmol h−1 g−1. • The photocatalytic activity of the ternary sample remains stable after four cycles. [ABSTRACT FROM AUTHOR]

This work introduces a novel method to construct Schottky junctions to boost the output performance of triboelectric nanogenerators (TENGs). Perovskite barium zirconium titanate (BZT) core/metal silver shell nanoparticles are synthesized to be embedded into electrospun polyvinylidene fluoride‐co‐hexafluoropropylene (PVDF‐HFP) nanofibers before they are used as tribo‐negative layers. The output power of TENGs with composite fiber mat exhibited >600% increase compared to that with neat polymer fiber mat. The best TENG achieved 1339 V in open‐circuit voltage, 40 µA in short‐circuit current and 47.9 W m−2 in power density. The Schottky junctions increased charge carrier density in tribo‐layers, ensuring a high charge transfer rate while keeping the content of conductive fillers low, thus avoiding charge loss and improving performance. These TENGs are utilized to power radio frequency identification (RFID) tags for backscatter communication (BackCom) systems, enabling ultra‐massive connectivity in the 6G wireless networks and reducing information communications technology systems' carbon footprint. Specifically, TENGs are used to provide an additional energy source to the passive tags. Results show that TENGs can boost power for BackCom and increase the communication range by 386%. This timely contribution offers a novel route for sustainable 6G applications by exploiting the expanded communication range of BackCom tags. [ABSTRACT FROM AUTHOR]

Vanadium-carbide (V 2 C) MXenes have received scientific attention for their thinner structure, multiple oxidation states, and excellent conductivity, which can effectively serve as electron-sinking sites to suppress the backward recombination of electrons and holes. Herein, well-structured V 2 C/g-C 3 N 4 nanohybrids were designed to promote photocatalytic hydrogen production. Stronger interfacial contact between 2D/2D V 2 C/g-C 3 N 4 proffers 4.23-fold more H 2 yield than pristine g-C 3 N 4 with a maximal rate of 360 μmol g−1 h−1. The loading of V 2 C improves the light absorption capability and facilitates the charge transfer for photo-redox reaction. However, h+ accumulation fosters the degradation kinetics over consecutive cycles, which drives the homolytic cleavage of the g-C 3 N 4 by hydroxyl radical (• OH). The tremendous decline in the photostability test over methanol-containing sacrificial reagents is consistent with the reduction of g-C 3 N 4 functional units, corroborating the structural breaking. Employing TEOA as a hole scavenger slows the homolytic decomposition of g-C 3 N 4 , which could act as a binding ligand in protecting the g-C 3 N 4 surface. Stronger intermolecular forces between the heterogeneous molecules with excellent scavenging activity effectively trap accumulated h+ and slow down the degradation kinetics. The findings of this work not only contribute to the scientific understanding of vanadium-based MXenes in photocatalytic hydrogen production but also lay the foundation for understanding the mechanistic structure of g-C 3 N 4. [Display omitted] • Fabrication of V 2 C/g-C 3 N 4 with sheet-on-layer morphology for photocatalytic hydrogen production. • A large interface barrier formation in V 2 C/g-C 3 N 4 promotes photocatalytic hydrogen production. • 2D/2D V 2 C/g-C 3 N 4 proffers 4.23-fold photocatalytic enhancement than pristine g-C 3 N 4. • Gradual declination in photostability with methanol was due to the possible decomposition of g-C 3 N 4 through • OH attack. • A continuous and stable H 2 yield was obtained using TEOA due to the formation of the protective layer. [ABSTRACT FROM AUTHOR]

Photocatalytic conversion of H2O and CO2 into solar fuels is considered to be a green and renewable technology while photocatalytic performance is hampered by the severe recombination of photogenerated electron–hole pairs. Drawing inspiration from the concepts of the electrons transfer layer (ETL) and the holes transfer layer (HTL) in perovskite solar cells, a multicomponent photocatalyst SrTiO3/NiO/NiS that incorporates p–n heterojunction and Schottky junction is constructed for converting solar energy into easily storable solar fuels. The NiS and NiO play the roles analogy to the ETL and the HTL which accomplishes the reverse migration of electrons and holes, accordingly, SrTiO3/NiO/NiS exhibits a noticeable enhancement in photocatalytic performance. However, the lack of direct observation of charge transfer pathways in complex multicomponent photocatalysts makes it challenging to thoroughly investigate their catalytic mechanisms. Herein, the in situ irradiation X‐ray photoelectron spectroscopy (ISI–XPS) is employed to track photogenerated charges migration pathways between microscopic heterogeneous interfaces, thereby providing a comprehensive elucidation of the catalytic mechanism and heterojunction formation process by integrating the photoelectrochemical tests. This study not only serves as compelling evidence for the capability of ISI–XPS in directly and accurately tracking charge transfer pathways but also as an intriguing highlight within the catalyst design strategy. [ABSTRACT FROM AUTHOR]

CdTiO 3 /Ti 3 C 2 MXene (CdTiO 3 /TCM) heterojunctions were created using coordination-solvothermal synthesis, effectively addressing the rapid recombination and slow migration of photogenerated carriers in single semiconductor photocatalysts. The CdTiO 3 /TCM heterojunction consists of shuttle-like CdTiO 3 structures implanted on the surface of multilayered Ti 3 C 2 MXene, significantly enhancing the specific surface area and visible light capture capability. The photocatalytic degradation rate constant of CdTiO 3 /TCM-B under visible light for Rhodamine B (RhB) reached 8.7 ×10 – 3 min – 1, 7.25 times that of pure CdTiO 3. CdTiO 3 /TCM-B maintained high degradation activity even after five cycles of use. Experimental results indicate that superoxide radicals (•O 2 – ) and hydroxyl radicals (•OH) were the main active species in the degradation process of RhB. Analysis of photoelectric properties and band structure revealed the role of the heterojunction structure in promoting the separation and transfer of photogenerated charges. The results confirm that Ti 3 C 2 MXene, as a cocatalyst for CdTiO 3 , can significantly improve photocatalytic performance, demonstrating the potential for developing new visible light photocatalysts. [Display omitted] • CdTiO 3 /Ti 3 C 2 MXene was synthesized via a straightforward coordination-solvothermal method. • Integrating CdTiO 3 particles on Ti 3 C 2 MXene layers in a shuttle-like configuration. • Schottky junction heterojunction formed, enhancing charge transfer and separation. • Superior photocatalysis in degrading rhodamine B under visible light. [ABSTRACT FROM AUTHOR]

[Display omitted] Solar-driven photocatalytic H 2 evolution could tackle the issue of fossil fuels-triggered greenhouse gas emission with sustainable clean energy. However, splitting water into hydrogen with high performance by a single semiconductor is challenging because of the poor charge separation efficiency. Herein, a novel ternary Cu@TiO 2 -Cu 2 O hybrid photocatalyst with multiple charge transfer channels has been designed for efficient solar-to-hydrogen evolution. Indeed, the ternary Cu@TiO 2 -Cu 2 O hybrid by coupling Cu@TiO 2 with Cu 2 O nanoparticles shows highly-efficient photocatalytic hydrogen generation with rate of 12000.6 μmol·g−1·h−1, which is 4.4, 2.1, and 1.9 times higher than the pure TiO 2 (2728.8 μmol·g−1·h−1), binary Cu@TiO 2 (5595.5 μmol·g−1·h−1), and TiO 2 -Cu 2 O (6076.8 μmol·g−1·h−1) composite, respectively. In such a Cu@TiO 2 -Cu 2 O hybrid, the formed internal electric field in the TiO 2 -Cu 2 O p-n junction allows the electrons in Cu 2 O to migrate to TiO 2 , while the electrons in the CB of TiO 2 could flow into Cu via the Schottky junction at the Cu@TiO 2 interface. In this regard, a multiple charge transfer is achieved between the Cu@TiO 2 and Cu 2 O, which facilitates promoted charge separation and results in the construction of electron-accumulated center (Cu) and hole-enriched surface (Cu 2 O). This p-n/Schottky junctions with steered charge transfer assists the hydrogen production upon the Cu@TiO 2 -Cu 2 O ternary photocatalyst. [ABSTRACT FROM AUTHOR]

The purposeful modulation of interfacial charge transfer pathways in heterogeneous structures is an innovative and feasible strategy to improve photocatalysis efficiency. However, it is often characterized by difficulties in charge separation and transport and the high charge recombination limits its applications. Herein, a Cd 0.3 Zn 0.7 S-based heterostructure of Cd 0.3 Zn 0.7 S@Ti 3 C 2 /Ag/CeO 2 was fabricated in which the efficient electron transfer route was designed by synergistic action of Z-scheme and Schottky junction. Serial characterizations and Density-Functional Theory calculations identify the Schottky junction promoted the electrons in Cd 0.3 Zn 0.7 S to transfer to Ti 3 C 2 , whereas the Z-scheme heterojunction accelerated the electrons transfer from CeO 2 to Cd 0.3 Zn 0.7 S@Ti 3 C 2 with Ag acting as the electronic intermediary. Significantly, the optimized Cd 0.3 Zn 0.7 S@Ti 3 C 2 /Ag/CeO 2 exhibited stronger photocatalytic H 2 evolution of 16.3 mmol·g−1·h−1 with an apparent quantum efficiency of 29.8 % at 420 nm, which was 4.2 times higher than the pristine Cd 0.3 Zn 0.7 S material. This work offers valuable insights into realizing the desired charge transfer route through artificial heterointerface and a new possibility for applying Cd 1-x Zn x S materials in photocatalytic hydrogen production. [ABSTRACT FROM AUTHOR]

• The hierarchical CuS@SnS 2 p-n heterojunction hollow cubes were fabricated. • The synergy of hollow cubes and p-n heterojunction enhanced photocatalytic CO 2 reduction. • The addition of Au nanoparticles was conducive to binding and reducing CO 2 molecules. • The synergy of p-n heterojunction and Schottky junction accelerated charge transfer and separation. During the photocatalytic CO 2 reduction process, fast charge transport, abundant active sites, and high visible light utilization in photocatalysts are key to achieving excellent CO 2 conversion efficiency. In this work, we have designed and prepared hierarchical CuS@SnS 2 p-n heterostructure hollow cubes for photocatalytic CO 2 reduction. First, a monolayer of CuS was in situ generated on the pre-prepared Cu 2 O cubes to construct core–shell Cu 2 O@CuS cubes by sulfidation of Cu 2 O cubes. The following etching process led to the formation of CuS hollow cubes. Finally, the hierarchical CuS@SnS 2 p-n heterostructure hollow cubes were obtained by growing SnS 2 nanosheets on the CuS hollow cubes. The prepared CuS@SnS 2 p-n heterostructure hollow cubes showed an improved photocatalytic CO 2 reduction activity compared with the bare CuS and SnS 2 control samples. The p-n heterojunction formed between SnS 2 and CuS as well as its hollow structure enhanced the charge carrier separation efficiency and the light absorption capacity of the hybrid catalyst. Furthermore, after the decoration of Au nanoparticles, the formed Schottky junction further discouraged the charge carrier recombination. Thus, the cooperative p-n heterojunction and Schottky junction greatly facilitated photocatalytic CO 2 reduction, and exhibiting the maximum CO and CH 4 yields of 140.1 and 77.5 μmol g−1 h−1, respectively. This work presents an efficient design of high-performance catalysts for photocatalytic CO 2 reduction. [ABSTRACT FROM AUTHOR]

• Ru 0.7 Cu 0.3 /W 18 O 49 Schottky junction is synthesized. • Metallic Ru 0.7 Cu 0.3 exhibits LSPR effects, enhancing AB hydrolysis activity. • The photocatalytic mechanism for H 2 generation is systematically expounded. Photocatalytic hydrogen (H 2) production from ammonia borane (AB) hydrolysis is a promising pathway for generating clean energy. Constructing appropriate heterojunctions represents an efficient strategy for enhancing the catalytic activity. Herein, a Ru 0.7 Cu 0.3 /W 18 O 49 Schottky junction is successfully designed, which greatly enhances transfer and separation of photogenerated charge carriers. Moreover, the metallic Ru 0.7 Cu 0.3 exhibits localized surface plasmon resonance (LSPR), which greatly enhances the light harvesting capability. As expected, the optimized Ru 0.7 Cu 0.3 /W 18 O 49 photocatalyst exhibits a superior visible-light-driven H 2 generation yield of 880 mL min−1 g−1 with excellent stability. The turnover frequency (TOF) value of Ru 0.7 Cu 0.3 /W 18 O 49 was found to be 1.44 times higher under visible light irradiation compared to the dark condition, achieving 133.1 min−1. The present study establishes a pioneering approach for the systematic design of highly efficient and durable heterostructure catalysts. [ABSTRACT FROM AUTHOR]

Environmental crisis aroused from the Cr(VI)-containing wastewater has received much attention, due to the cancer-causing and mutagenic feature of Cr(VI). Photocatalytic technology has been considered to be a favorable contestant for coping with Cr(VI)-containing effluent. In this study, Ti 3 C 2 MXene/Zn 3 In 2 S 6 Schottky junctions with different content of Ti 3 C 2 MXene were prepared for Cr(VI) photoreduction. The inherent physical and photoelectrochemical characters of the obtained Ti 3 C 2 MXene/Zn 3 In 2 S 6 Schottky junctions were fully characterized. Compared with the pure Zn 3 In 2 S 6 , all the nanocomposites showed enhanced photocatalytic performance, the apparent kinetic constant of the optimized sample was 3.17 times the height of the Zn 3 In 2 S 6. The improved photoreduction performance largely originated from the effectual separation and transfer of the photoexcited charge carriers. In the meantime, the deleterious role of superoxide radicals for Cr(VI) photoreduction was confirmed. It is anticipated this research can deliver a new-fangled vision for constructing efficient photocatalyst for Cr(VI) photoreduction. [ABSTRACT FROM AUTHOR]

Construction of Schottky junctions based DUT-67 and Pd nanosheet with enhanced charge carrier separation efficiency for efficient photoreduction of CO 2. [Display omitted] • DUT-67 decorated with Pd nanosheet was prepared. • 0.3-Pd/DUT-67 had considerable photocatalytic CO 2 reduction to CO efficiency of 48.6 μmol g−1. • Schottky barrier at Pd/DUT-67 interface boosts separation of electron-hole pairs. The separation, transfer and recombination of charge often affect the rate of photocatalytic reduction of CO 2. Schottky junctions can promote the rapid separation of space charge. Therefore, in this paper, Pd nanosheets were grown on the surface of DUT-67 by a hydrothermal method, and a Schottky junction was constructed between DUT-67 and Pd. Under the action of the Schottky junction, the CO yield of 0.3-Pd/DUT-67 reached 12.15 μmol/g/h, which was 17 times higher than that of DUT-67. Efficient charge transfer was demonstrated in photochemical experiments. The large specific surface area and the increased light utilization rate also contributed to the increase in the CO 2 reduction efficiency. In addition, the mechanism of Pd/DUT-67 photocatalytic reduction of CO 2 was proposed. [ABSTRACT FROM AUTHOR]

Schottky junction and p-n heterojunction are widely employed to enhance the charge transfer during the photocatalysis process. Herein, Cu and Cu 3 P co-modified TiO 2 nanosheet hybrid (Cu–Cu 3 P/TiO 2) was fabricated using an in situ hydrothermal method. The ternary composite achieved the superior H 2 evolution rate of 6915.7 μmol g−1 h−1 under simulated sunlight, which was higher than that of Cu/TiO 2 (4643.4 μmol g−1 h−1) and Cu 3 P/TiO 2 (6315.8 μmol g−1 h−1) and pure TiO 2 (415.7 μmol g−1 h−1). The enhanced activity can be attributed to the collaboration effect of Schottky junction and p-n heterojunction among Cu/TiO 2 and Cu 3 P/TiO 2 , which can harvest the visible light, reduce the recombination of charge carriers and lower the overpotential of H 2 evolution, leading to a fast H 2 evolution kinetics. This work develops a feasible method for the exploration of H 2 evolution photocatalyst with outstanding charge separation properties. [Display omitted] • Cu and Cu 3 P co-modified TiO 2 nanosheet was fabricated via in situ hydrothermal method. • The Schottky junction and p-n heterojunction work together to enhance the H 2 evolution efficiency. • Low recombination rate of electron-hole pairs is achieved by the dual heterojunction. • The charge transfer pathway was revealed by radical trapping test using TA and NBT as indicator. [ABSTRACT FROM AUTHOR]

(040/110)-BiVO 4 facet isotype heterojunction and r-GO aided all-solid-state Z-scheme charge transfer dynamics In 2 S 3 @r-GO@(040/110)-BiVO 4 ternary hybrid towards an augmented photocatalytic redox activity. Efficient interfacial exciton transfer and separation have been regarded as the foremost confront of semiconductor oriented photocatalysis. The simultaneous discovery of crystal facet isotype heterojunction across the (0 4 0)-reduction and (1 1 0)-oxidation facet of monoclinic scheelite BiVO 4 crystal; and Schottky junction at the interfacial region of BiVO 4 crystal with well-exposed functional (0 4 0) facet and r-GO sheets has been reflected as an efficient electron injection route. In this context lucrative architecture of a high productive all-solid-state Z-scheme charge transfer dynamics In 2 S 3 @r-GO@(040/110)-BiVO 4 isotype ternary hybrid photocatalyst was carried out and well-validated by FESEM and HRTEM analyses. Photoelectrochemical measurements have revealed that the accumulated photo-electrons over the exposed (0 4 0)-crystal facet of BiVO 4 truncated bipyramid easily cross the minor Schottky junction to expedite the unidirectional injection to the π–π conjugated two-dimensional planar r-GO structure. Besides, subsequent trapping of the injected electrons by the photoinduced holes of In 2 S 3 leading to a superior charge carrier separation in the material, validated by PL, EIS, Mott-Schottky, and transient photocurrent analysis. Perceptibly, this intimate interfacial interacted crystal facet dependent electron shuttle provided a longer life span electrons and holes to settle in the conduction band of In 2 S 3 and valence band of (1 1 0)-BiVO 4 , respectively, for elevated photo-activity efficiency. The In 2 S 3 @r-GO@(040/110)-BiVO 4 ternary hybrid contributes 89.7% of Ciprofloxacin (CIP) detoxification in 150 min and 885.43 µmol of O 2 evolution in 120 min. More in, the constructive interrelations of resultant Physico-chemical, photoelectrochemical, and augmented photocatalytic redox efficiency were well-illustrated. This unique association semiconductor ternary hybrid photocatalyst via metal-free mediating agent crystal-facet sandwich structure will provide a scientific innovative basis for rational design and realization of advanced Z-scheme photocatalytic system for energy and environment application. [ABSTRACT FROM AUTHOR]

Facing the demand of cleaning energy, the development of efficient photocatalysts for hydrogen evolution is a promising way to realize solar-to-chemical energy conversion for solving energy crisis. Hence, a novel hierarchical Ti 3 C 2 MXene@TiO 2 /ZnIn 2 S 4 photocatalyst with rapid charge transfer channels was constructed by two-step hydrothermal for efficient hydrogen production, adopting hydrothermal oxidation to in-situ synthesize Ti 3 C 2 MXene embedded with TiO 2 nanosheets (M@TiO 2), which was applied to load ZnIn 2 S 4 (ZIS). The hybridized photocatalyst with optimized ZIS amount had a hydrogen generation rate of 1185.8 μmol/g/h, which was higher than that of M@TiO 2 and pure ZIS. That was originated from the outstanding light harvesting of ZIS and Ti 3 C 2 , sufficient active sites of Ti 3 C 2 , intimate interfacial contact, and efficient separation and transfer of photogenerated charges via heterojunction. The favorable and rapid charge transfer routes included type-II heterojunction between ZIS and TiO 2 nanosheets, Schottky junction of Ti 3 C 2 /semiconductor, and metallic Ti 3 C 2 with high conductivity. This work revealed the Schottky junction forming between ZIS and Ti 3 C 2 , and hierarchical M@TiO 2 could be served as advantageous platform and efficient cocatalyst to construct MXene-based photocatalyst. [ABSTRACT FROM AUTHOR]

This study has widely described the fabrication and performance of a series of Ag–CeO2 Schottky plasmonic photocatalysts under visible light irradiation. A conventional wetness incipient impregnation technique has been utilized to load Ag metal on the surface of CeO2 nanoparticles synthesized by the hydrothermal method. The as-synthesized photocatalysts have been identified using combined characterizations of XRD, FTIR, FESEM, EDS, TEM and UV–Vis DRS. The photocatalytic activity of as-synthesized samples has been investigated in terms of degradation efficiency of methylene blue (MB) as a function of involved operating factors including irradiation photon energy, irradiation time, pH, initial MB concentration, photocatalyst dose and amount of loaded Ag. All of the Ag–CeO2 samples have exhibited higher photocatalytic efficiencies than pure CeO2 with the order of 8%-Ag–CeO2 > 5%-Ag–CeO2 > 2%-Ag–CeO2 > pure CeO2. The enhanced photocatalytic activity has been ascribed to the improved light absorption toward visible irradiation photons due to the surface plasmon resonance, supported by the DRS results. A Schottky scheme photocatalytic mechanism that highlights charge transfer pattern has been developed for photodegradation rate. Photocatalytic process kinetics has been found to obey the pseudo-first-order expression according to the Langmuir–Hinshelwood model. [ABSTRACT FROM AUTHOR]

Here, we present a novel TU series based on Ti 3 C 2 nanosheets modified UiO-66-NH 2 with Schottky junction for photocatalytic H 2 evolution. • Ti 3 C 2 nanosheets were integrated with UiO-66-NH 2 for enhanced photocatalytic HER activity. • TU series displayed superior photocatalytic H 2 evolution activity and stability. • Spatial separation and transfer of charge carriers was realized by the Schottky junction. • Ti 3 C 2 nanosheets with functional groups possessed abundant active sites. • DFT calculations revealed O-TC possessed the most positive Fermi level and lowest ΔG H*. As newly-developing non-noble metallic co-catalysts, MXenes have attracted intensive attention as an ideal candidate to promote the photocatalytic H 2 -production activity. In this study, Ti 3 C 2 nanosheets prepared by intercalation were further attached to porous MOFs (UiO-66-NH 2) via one-pot hydrothermal method to form face-to-face intimate contact. The obtained TU10 presented the highest photocatalytic H 2 -evolution rates in TU series, exceeding that of pure UiO-66-NH 2 by approximately 8 times. The speculation revolving about enhanced photocatalytic H 2 -production performance was proposed as the presence of exposed active sites at the edge of Ti 3 C 2 nanosheets and spatial separation and transfer of charge carriers introduced by the Schottky junction at TU series interface, which accumulated the photo-induced electrons on the surface of Ti 3 C 2 nanosheets and improved its electron-donating ability. The DFT calculations revealed that O-terminated Ti 3 C 2 possessed the most positive Fermi level and the lowest Gibbs free energy (|ΔG H* | = 0.08 ≈ 0). This work may provide new insights for constructing MXenes/MOFs structure based on Schottky junction effect to achieve high photocatalytic H 2 -production performance. [ABSTRACT FROM AUTHOR]

Utilize the two-dimensional semiconductor superiorities and noble-metal-free Schottky junction effect to boost the photocatalytic performance. • Synergistically utilize 2D semiconductor superiorities and noble-metal-free Schottky junction to boost the photocatalytic performance. • The stronger redox capability and the fast charge kinetics synergistically boosted the photocatalytic performance. • By ESR analysis and theoretical calculation, the photocatalytic mechanism was researched in detail. Sunlight-driven photocatalysis holds great promise for alleviating the energy and environmental crises. For the visible-light-driven bare semiconductor, there is an irreconcilable contradiction between the light absorption and strong redox capabilities. Here, we reported a predictable design for improving the photocatalytic performance via regulating the bandgap and accelerating the charge kinetics of the semiconductor. Taken together, utilize two-dimensional (2D) structure to essentially increase the bandgap of the semiconductor for gaining the higher transfer and separation of the photogenerated electron-hole pairs and the stronger redox capabilities; and accelerate charge kinetics via the driving force from the Schottky junction. Meanwhile, the Schottky barrier prevents the photogenerated electrons trapped by a noble-metal-free electron acceptor from dually recombining. Additionally, the energy transfer process of the photocatalytic reaction was also researched in detail, aligning well with the photocatalytic mechanism. [ABSTRACT FROM AUTHOR]

Abstract The annealed Ti 3 C 2 T x MXenes retained original layered morphology and gave rise to the formation of TiO 2 is anticipated to achieve improved photocatalytic hydrogen evolution performance as a noble-metal-free co-catalyst. In this work, a novel Ti 3 C 2 /TiO 2 /UiO-66-NH 2 hybrid was rationally designed for the first time by simply introducing annealed Ti 3 C 2 T x MXenes over water-stable Zr-MOFs (UiO-66-NH 2) precursors via a facile hydrothermal process. As expected, the rationally designed Ti 3 C 2 /TiO 2 /UiO-66-NH 2 displayed significantly improvement in photocatalytic H 2 performance (1980 μmol·h−1·g−1) than pristine UiO-66-NH 2 under simulated sunlight irradiation. The excellent photocatalytic HER activity can be attributed to the formation of multi-interfaces in Ti 3 C 2 /TiO 2 /UiO-66-NH 2 , including Ti 3 C 2 /TiO 2 /UiO-66-NH 2 , Ti 3 C 2 /TiO 2 and Ti 3 C 2 /UiO-66-NH 2 interfaces, which constructed multiple pathways at the interfaces with Schottky junctions to accelerate the separation and transfer of charge carriers and endowed the accumulation of photo-generated electrons on the surface of Ti 3 C 2. This work expanded the possibility of porous MOFs for the development of efficient photocatalytic water splitting using annealed MXenes. Graphical abstract Image 1 Highlights • Ti 3 C 2 /TiO 2 /UiO-66-NH 2 was obtained by introducing annealed Ti 3 C 2 T x over Zr-MOFs. • Ti 3 C 2 /TiO 2 /UiO-66-NH 2 presented superior photocatlytic H 2 -production activity. • Three types of contact interfaces with Schottky junctions were depicted. • The enhanced charge transfer efficiency was investigated in detail. [ABSTRACT FROM AUTHOR]

We report an in situ constructed Mo@MoO 3 Schottky junction and investigate its synergistic interaction with oxygen vacancies for efficient N 2 photoreduction, where the Schottky junction forms a charge transfer channel during the photocatalytic reaction. The oxygen vacancies, while capturing electrons to activate N 2 , together with the Mo element, expand the light absorption range of the catalyst, allowing more efficient transfer of excited electrons to the active site for nitrogen fixation. [Display omitted] • In-situ construction of Mo@MoO 3 Schottky junctions. • Photocatalytic nitrogen fixation by synergistic interaction of Schottky junctions and oxygen vacancies. • Nanosheets of Mo@MoO 3 are more conducive to the rapid transfer of photogenerated electrons in photocatalytic reactions. Defect engineering is a promising technique that can activate nitrogen by injecting electrons into the anti-bonding molecular orbital of nitrogen through anion vacancies. Moreover, compared to a single component, Schottky junctions can effectively overcome rapid electron recombination, thereby significantly enhancing photoelectron utilization efficiency. In this work, we prepared Mo modified MoO 3 nanosheets with abundant oxygen vacancies by a solvothermal method and investigated the effect of synergistic interactions between Schottky junctions and oxygen vacancies on the photocatalytic performance of N 2 reduction reaction (NRR). The photocatalytic nitrogen fixation performance of Mo@MoO 3 nanosheets (MoO 3 -6) reached 50.78 μmol·g−1·h−1 without any scavenger, which was about 3 times that of commercial MoO 3. The Schottky barrier creates a built-in electric field generating charge transfer channels during the photocatalytic reaction, while the oxygen vacancies trap electrons to activate N 2 , and together with Mo, broaden the light absorption range of the catalyst, facilitating more efficient transfer of excited electrons to the active site. The synergetic advantages of Schottky junctions and oxygen vacancies are exploited in advancing the photocatalytic effect, providing new opportunities and challenges for the development of metal oxide-based materials. [ABSTRACT FROM AUTHOR]

Ni/ZnIn 2 S 4 nanosheet assembly with sulfur vacancy and Schottky junction (Ni/DZIS) is fabricated and shows much better the photocatalytic hydrogen evolution rate without any noble metal cocatalysts. The improved photocatalytic performance is mainly attributed to the synergism of sulfur vacancy and Schottky junction accelerating the photogenerated charge transfer and thus inhibiting the charge recombination. [Display omitted] • Fabrication of Ni/ZnIn 2 S 4 nanosheet assembly with sulfur vacancy and Schottky junction (Ni/DZIS) through facile ethanediol-assisted solvothermal method. • The location of Ni at the hollow site of three S atoms next to sulfur vacancy on the ZnIn 2 S 4 (0 0 6) face. • The photocatalytic hydrogen evolution rate of Ni/DZIS up to 703 μmol g−1h−1 without any noble metal cocatalysts. Surface and interface engineering play vital roles on improving the photocatalytic hydrogen evolution. Herein, Ni/ZnIn 2 S 4 nanosheet assembly with sulfur vacancy and Schottky junction (Ni/DZIS) is fabricated through facile ethanediol-assisted solvothermal method. Density functional theory (DFT) calculation reveals that the Ni is absorbed at the hollow site of three S atoms next to sulfur vacancy on the ZnIn 2 S 4 (0 0 6) face due to the formation of sulfur vacancy. The resultant Ni/DZIS Schottky junction exhibits high photocatalytic H 2 evolution rate of 703 μmol g−1h−1 without any noble metal cocatalysts, which is 2.6 times higher than that of pristine ZnIn 2 S 4 nanosheets. The improved photocatalytic performance is mainly attributed to the synergism of sulfur vacancy and Schottky junction accelerating the photogenerated charge transfer and thus inhibiting the charge recombination. Moreover, the photocatalytic performance of Ni/DZIS nearly keeps constant even after six recycles, indicating the high stability and potential applications in field of energy. This work provides a convenient strategy for constructing efficient defective heterojunction assembly photocatalysts via surface and interface engineering. [ABSTRACT FROM AUTHOR]

• Noble-metal-free CuSe decorated porous g-C 3 N 4 composites were obtained. • The composites exhibited excellent CO 2 photoreduction activity and stability. • Photocatalytic mechanism is discussed. Photocatalytic CO 2 reduction based on g-C 3 N 4 with inexpensive, efficient, stable, and suitable energy band structure, serve as a promising candidate for alleviating the greenhouse effect. However, g-C 3 N 4 still suffers from low CO 2 photoreduction performance owing to severe charge recombination and high surface reaction energy barriers. Herein, porous g-C 3 N 4 /CuSe (PCN/CS) Schottky heterojunctions were fabricated by loading non-precious CS nanosheets on porous PCN nanosheets, contributing to a decreased the reaction energy barrier and elevated charge separation. The improved charge separation by Schottky heterojunction were unveiled by the transient photocurrents as well as photoluminescence (PL) spectra. The photogenerated electrons transfer from PCN to CS was demonstrated by density functional theory (DFT) calculations and XPS analysis. Meanwhile, CS lowers the energy berries and serves as an active site for CO 2 reduction, thus accelerating the CO 2 photoreduction processes. The experimental results manifest that the CO 2 photoreduction efficiency of PCN/CS was significantly higher than that of pure PCN and CS. The efficiency of CO 2 photoreduction to CO in the composite sample was 25.03 μmol·g−1·h−1, which was 6.53 times and 2.45 times higher than that of pure CS and PCN, respectively. This work provides a new insight on the design of Schottky junctions by anchoring non-precious metal on PCN for ameliorated CO 2 photoreduction performance. [ABSTRACT FROM AUTHOR]

The electrochemical sensors with the ability of biomolecule detection can be used for human life and health monitoring. In this work, we developed an electrochemical sensor with a Schottky junction by electrostatic interaction, composed of Nb 2 C MXene and MnFe 2 O 4. Large reactive groups (O, OH, Cl, or F) are observed at the ends of the Nb 2 C MXene surface. Meanwhile, there are abundant oxygen vacancies and surfaces of MnFe 2 O 4 which bring it favorable heterogeneous catalytic properties. Among them, the chemical self-assembly of MnFe 2 O 4 nanoparticles on Nb 2 C MXene enhances the binding strength of the material through electrostatic interaction, promotes charge transfer across the interface, and modulates the electronic and nanostructural characteristics of the N-MFO (MnFe 2 O 4 /Nb 2 C MXene). The results demonstrate that the sensing performance of N-MFO4 for Acetaminophen (AP) and Dopamine (DA) is significantly improved compared to Nb 2 C MXene and MnFe 2 O 4 modified electrodes, respectively. The obtained limits of detection (LOD) of N-MFO4 modified electrode for AP and DA being 0.079 and 0.070 μM, respectively. The combination of electrodes modified with highly active nanomaterials is supposed to build a portable electrochemical analysis system with high sensitivity, good selectivity, favorable stability, simple operation and low cost, and promote the application of electrochemical sensors in related fields. [Display omitted] • Self-assembled N-MFO materials with electrostatically bonded Schottky junctions. • Heterogeneous structure of N-MFO with high conductivity and large active surface. • Dual-function N-MFO sensors exhibit excellent detection characteristics. [ABSTRACT FROM AUTHOR]

[Display omitted] • Investigation of the structural and electronic properties of 0D Ti 2 CO 2. • Metallic 0D Ti 2 CO 2 serving as an electron acceptor. • Effective separation of photo-excited carriers in 0D Ti 2 CO 2 /2D g-C 3 N 4 Schottky-junction. • High hydrogen evolution reaction activity at the metal sites at the edge of 0D Ti 2 CO 2. The construction of Schottky junctions is considered to be an efficient way to boost spatial charge separation and transfer in photocatalytic systems. In this work, we construct the Schottky junction using zero-dimensional (0D) Ti 2 CO 2 nanoclusters (TCO) and two-dimensional (2D) g-C 3 N 4 (GCN), denoted as TCO/GCN. The interfacial interaction, separation of photogenerated carriers, and reaction driving force of the TCO/GCN have been investigated based on density functional theory (DFT) calculations. TCO can serve as an electron acceptor due to the larger work function relative to the semiconductor GCN. The band bending caused by the interfacial charge prevents the electrons from flowing back to the semiconductor, which can effectively separate the photo-excited carriers. The metal sites exposed at the edge of TCO exhibit high hydrogen evolution reaction (HER) activity. This study provides a new idea for the development of 0D/2D Schottky junction photocatalysts. [ABSTRACT FROM AUTHOR]

[Display omitted] • A cocatalyst Ti 3 C 2 T x /1T-WS 2 is synthesized by growing 1T-WS 2 on ultrathin Ti 3 C 2 T x. • The different CB potentials result in rapid charge transfer from CdS to 1T-WS 2. • Ti 3 C 2 T x further accelerates charge transfer and promotes charge separation. • The H 2 evolution rate of 4% Ti 3 C 2 T x /1T-WS 2 /CdS reaches 12.39 mmol∙h−1∙g−1. Accelerating charge transfer and separation is the core mission of promoting photocatalytic H 2 production activity. Here, the hybrid cocatalyst Ti 3 C 2 T x /1T-WS 2 is synthesized by in situ growth of 1T-WS 2 on the ultrathin Ti 3 C 2 T x surface using a solvothermal method for enhancing the photocatalytic activity of CdS. The difference in CB potentials between CdS and 1T-WS 2 results in the rapid migration of photogenerated electrons from CdS to 1T-WS 2. More importantly, because of the intimate Schottky interfacial contact between Ti 3 C 2 T x and 1T-WS 2 , the electrons on the 1T-WS 2 further rapidly transfer to the surface of Ti 3 C 2 T x , thereby enhancing the separation efficiency of photogenerated electrons. Compared with the single Ti 3 C 2 T x (4.66 mmol∙g−1∙h−1) and 1T-WS 2 (10.65 mmol∙g−1∙h−1), the hybrid Ti 3 C 2 T x /1T-WS 2 cocatalyst (12.39 mmol∙h−1∙g−1) has more excellent catalytic hydrogen evolution performance. The apparent quantum efficiency (AQE) Ti 3 C 2 T x /1T-WS 2 /CdS at λ = 420 nm reaches 50.9%. This work is helpful to understand the mechanism of the hybrid cocatalyst to improve charge separation. [ABSTRACT FROM AUTHOR]

[Display omitted] • MXene/MIL(Fe) with Fe-protoporphyrin bridging was applied as photo-Fenton catalyst. • Biomimetic Fe-protoporphyrin showed high O 2 -carrying capacity for H 2 O 2 generation. • Schottky barrier enhanced charge transfer and O 2 reduction for H 2 O 2 generation. • MXene/MIL(Fe)-POR exhibited 12 times higher H 2 O 2 production rate than MIL(Fe) • MXene/MIL(Fe)-POR showed 60 times higher TCL removal rate than reported catalysts. Efficient and deep degradation for organic contaminants in the absence of externally supplied H 2 O 2 is still a challenge and research hotspot for photo-Fenton catalysis. In this work, a novel Ti 3 C 2 MXene/MIL-100(Fe) hybrid via Fe-protoporphyrin bridging was proposed to in-situ generate H 2 O 2 for photo-Fenton catalytic degradation of thiacloprid (TCL). The generated Schottky junction between MXene and MIL-100(Fe) and biomimetic oxygen-carrying from Fe-protoporphyrin constructed a synergistic system to promote H 2 O 2 generation and photo-Fenton reaction. As expected, MXene/MIL-100(Fe) exhibited 12 times higher of H 2 O 2 generation rate (reaching 1175.2 μmol/L under air-bubble), and 24 times of degradation rate and 3.7 times of mineralization rate for TCL compared to MIL-100(Fe). In addition, MXene/MIL-100(Fe) possessed 21–60 times higher TCL degradation rate than many of reported photo-Fenton catalysts in H 2 O 2 -free system. MXene/MIL-100(Fe) realized > 80 % TOC removal of TCL (80 mg/L) within 120 min, and exhibited excellent catalytic stability (>97 % TCL degradation) for 10 successive reuses. [ABSTRACT FROM AUTHOR]

In the present study, we have successfully formulated a dual heterojunction of g-C 3 N 4 /BiOCl@MXene-Ti 3 C 2 (GCBM) which was found to be highly active in the visible region. GCBM was found to be highly efficient for the degradation of an antibiotic, tetracycline (TC) as compared to the individual constituting units; g-C 3 N 4 and BiOCl. Maximum of 97% TC degradation rate was obtained within 90 min of visible light irradiation for initial concentration of 10 mg/L of TC. Optical analysis exhibited that the synthesized heterojunction showed high absorption in the complete spectrum. The reactive species specified by the scavenger study showed the major involvement of • O 2 − and • OH radicals. The charge transfer mechanism showed that 2 schemes were majorly involvement in which Z-scheme was formed between g-C 3 N 4 and BiOCl and Schottky junction was formed between g-C 3 N 4 and Mxene-Ti 3 C 2. The formation of Schottky junction helped in inhibiting the back transfer of photogenerated charges and thus, helped in reducing the recombination rate. The synthesized photocatalyst was found to be highly reusable and was studied for consecutive 5 cycles that generalized the high proficiency even after repetitive cycles. [Display omitted] • Visible-light active heterojunction g-C 3 N 4 /BiOCl@MXene-Ti 3 C 2 GCBM) was designed. • Z-scheme and Schottky junction was used for explaining the charge transfer. • MXene-Ti 3 C 2 reduced the chances of back reactions. • O 2 − and OH radicals were found to be the major reactive species. [ABSTRACT FROM AUTHOR]

• A novel self-powered PEC sensor was developed for CPF assay. • The Schottky junction was made for enhanced photoelectric conversion efficiency. • MLCT effect induced the excellent selectivity of the sensor. • The sensor can be used to determine CPF in apple and cucumber samples. Herein, a high-performance self-powered photoelectrochemical (PEC) sensor was fabricated for chlorpyrifos (CPF) assay based on the noble-metal-free AgBr/Ti 3 C 2 Schottky interface in fruit and vegetables. The Schottky barrier could provide an electron-transfer irreversible passage from AgBr to Ti 3 C 2 nanosheets, and thus improving the light absorption and efficiency of charge separation. Such Schottky interface exhibited an ultrasensitive and selective photocurrent response for CPF due to the metal–ligand charge transfer effect. Because Ti 3 C 2 MXene nanosheet had coordinative interaction with CPF and thus suppressed its photocurrent response of the Schottky interface, which was further confirmed by the electrochemical impedance spectra and X-ray photoelectron spectroscopy. The developed self-powered PEC sensor showed wide linear range (1 × 10−3 ∼ 1 ng L−1), low detection limit (0.33 pg L−1), limit of quantitation (1 pg L−1), good reproducibility and stability. The sensor was applied for the determination of CPF in river water, apple and cucumber samples with good satisfactory results. [ABSTRACT FROM AUTHOR]

The exploration of suitable anode materials to overcome key issues of electrode volume fluctuation and sluggish electronic/ionic transport dynamics caused by the large radius of sodium/potassium ions is an urgent need for energy storage. Herein, a heterogenetic nickel-iron selenide containing vacancies and schottky junctions within N-graphene porous matrix to realize external and internal charge transport is constructed via a one-pot in-situ carbonization and selenization route. In the composite, the iron selenide possessing metallic property acts as the conductor incorporated with nickel selenide semiconductor for constructing schottky junctions and vacancies to induce internal charge transfer and transport of the active material, and the N-graphene not only enhance the interparticle conductivity by bridging the selenides, but also relieve the volume fluctuation and keep integrity without agglomeration of nanocrystals. Profiting from the synergistic effect, the material exhibits boosted electrochemical properties for sodium (264 mA h g−1 after 1000 cycles at 1.0 A g−1) and potassium (115 mA h g−1 after 500 cycles at 0.5 A g−1) storage. And the thorough understanding of electrochemical mechanism on the raised performance is explicitly interpreted by combining ex-situ characterization results and density functional theoretical calculations. A heterogenetic nickel-iron selenide containing vacancies and schottky junctions within N-graphene porous matrix is constructed via a one-pot in-situ carbonization and selenization route. Profiting from the synergism of the interface engineering of the constituents, the constructed material exhibits boosted specific capacities, cyclic stabilities, and rate abilities for sodium/potassium ion batteries. [Display omitted] • Selenide with vacancies and junctions in porous N-graphene is in-situ constructed. • The NiSe/FeSe@pNGS delivers enhanced sodium and potassium storage properties. • The heterogenetic structure of the selenide to favor energy storage is explored. [ABSTRACT FROM AUTHOR]

Highlights: [•] All-inorganic hybrid metal–semiconductor networks with controlled size are synthesized. [•] We demonstrate different approaches to selectively contact the networks and single chains with planar electrodes. [•] Charge transport characterization of networks on different size from macroscopic to nanometer scale. [Copyright &y& Elsevier]

[Display omitted] • Ti 3 C 2 MXene@TiO 2 /CuInS 2 Schottky/s-scheme integrated heterojunctions were prepared by a two-step hydrothermal method. • Synergistic effect of Schottky junction and s-scheme heterojunction endows significantly improved charge transfer. • The ternary heterojunction shows excellent photocatalytic hydrogen production and outstanding cycling stability. • The photocatalytic mechanism was clarified by some representative characterizations. The development of novel and efficient heterojunction photocatalysts is still a challenging issue for achieving highly efficient solar-to-chemical energy conversion. Herein, we report the construction of Ti 3 C 2 MXene@TiO 2 /CuInS 2 (M@T/CIS) integrated Schottky/step-scheme (S-scheme) heterojunction by two-step hydrothermal process for boosting photocatalytic hydrogen generation activity. The as-prepared M@T/CIS hybrid photocatalysts exhibit the synergistic effects for enhanced visible-light harvesting, improved charge transfer and increased active site for photocatalytic H 2 evolution. They deliver a H 2 evolution rate of 356.27 μmol g-1h−1, which is ∼ 69 and 636 times higher than those of M@T and CIS, respectively, representing their potential applications towards photocatalytic H 2 evolution. [ABSTRACT FROM AUTHOR]

The unidirectional electrons transfer from TCN to NiS and charge density difference of C 3 N 4 /NiS (001). [Display omitted] • Explained the mechanism of Schottky junction based on the experiment and DFT data. • Given a detailed explanation about how and why the energy band of TCN was bent. • Clearly distinguished the two different charge transfer process from TCN to NiS. Despite plenty of works involve in Schottky junction to optimizing charge kinetics have been researched, some issues still bother us. For example, why photo-excited electrons transfer from semiconductor to metal in Schottky junction, and can we realize the formation of Schottky junction is the nature property of materials and unrelated to light, etc. To analyze the mechanism of Schottky junction, a novel 3D weed g-C 3 N 4 /flowerlike NiS composite (TCN/NiS) was designed. The existence of Schottky junction was proved by DFT calculations. The high charge separation efficiency in TCN/NiS was reflected in the photo-electrochemical characterization, and was also verified by the photocatalytic degradation of a representative organophosphorus pesticides chlorpyrifos with a high degradation efficiency of 86 %. Especially, about how and why the energy band of TCN bending, and why photo-excited electrons transfer from TCN to NiS were explained elaborated. The deep understanding of Schottky junction helps to construct high efficiency photocatalysts. [ABSTRACT FROM AUTHOR]

[Display omitted] • E ads (O 2) on SV and DV surfaces is 2–3 times as strong as that on defect-free BL. • The O 2 adsorption on SV and DV defective BL lacks energy barrier. • n -doping in the EG layer can be fully compensated by oxidizing the DV defective BL. • The DV-O-EG interface forms a p -type Schottky contact with a small SBH. • A p -type Ohmic contact was measured at the SV-O-EG interface. Adsorption and dissociation of molecular oxygen on a defective graphene buffer layer (BL) grown on Si-terminated SiC(0001) are herein studied by means of periodic DFT calculations coupled with the nudged elastic band method. We considered a single vacancy (SV) and a divacancy (DV) defective BL on SiC, with or without the uppermost epitaxial monolayer graphene (EG). The adsorption energy of O 2 on SV and DV surfaces, producing SV-O and DV-O oxidized systems, is between 2 and 3 times as strong as that on a defect-free BL surface and lacks an energy barrier. In addition, we demonstrate that the n -doping measured in the EG layer of SiC-BL-EG systems, which stems from the charge transfer in the SiC-BL interface, can be fully compensated by oxidizing the DV defective BL. The DV-O-EG interface forms a p -type Schottky contact with a small Schottky barrier height. Instead, a p -type Ohmic contact was measured at the SV-O-EG interface. [ABSTRACT FROM AUTHOR]

[Display omitted] • Integration of S-scheme/Schottky junctions and oxygen vacancies on SrTiO 3 is constructed. • Formed junctions enable the transfer of charges with direction. • Designed hybrid dramatically improves photocatalytic H 2 evolution activity. • Large-scale photocatalytic device (20 cm × 20 cm) is successfully demonstrated. The interfacial design and defect engineering are of huge interest for achieving efficient photocatalytic H 2 evolution using solar energy. In this work, we successfully integrated the Schottky junction and S-scheme heterojunction with oxygen vacancies to achieve the defective Ru/SrTiO 3 /TiO 2 hybrid photocatalyst. As verified by experimental studies, these junctions with defects fully exploit the benefits of interfacial charge separation and transport. It is demonstrated that the designed hybrid exhibits dramatically enhanced photocatalytic H 2 evolution rate with respect to pristine SrTiO 3 , high apparent quantum efficiency at 365 nm irradiation as well as excellent stability. Furthermore, the Ru/SrTiO 3 /TiO 2 based device photocatalyst also displays the excellent H 2 evolution activity with easy recycle nature. This finding provides a newfangled thought for developing highly efficient hybrid materials for photocatalytic H 2 evolution. [ABSTRACT FROM AUTHOR]

[Display omitted] • The MXene/Ag 2 S catalyst is constructed by chemical deposition and electrostatically driven self-assembly. • The MXene/Ag 2 S has excellent visible light absorption performance under visible light (>420 nm). • The prepared photocatalyst can efficiently remove MB and tetracycline hydrochloride, with a removal rate of >90%. • Under the influence of mixed dyes and inorganic salts, the photocatalytic effect of the catalyst is still significant. • After 8 cycles of experiments, the photocatalytic activity is >90%. A novel visible-light-driven uniform Schottky junction MXene/Ag 2 S catalyst is constructed by chemical deposition and electrostatically driven self-assembly to deposit Ag 2 S 3D MXene gel's surface. In this study, various characterization tests show that MXene/Ag 2 S-2 photocatalyst has excellent visible light absorption performance under visible light (>420 nm). To explore the source of the excellent charge separation performance of Schottky junction, possible charge transfer mechanisms of Schottky junction, and the synergistic effect of silver ion plasmon resonance effect are proposed. We proved the charge transfer mechanism of the Schottky junction and also captured the active species capture experiments. It can be speculated that all active species affect the photocatalytic reaction in the order of O 2 − > e− > h+ >OH. Simultaneously, the photocatalytic system would have a small amount of silver ion reduction in the plasmon resonance effect during the photocatalysis process, which can be synergistic with the Schottky junction. Besides, the Schottky junction MXene/Ag 2 S has relatively stable photocatalytic performance and recovery capability. The current work demonstrates a mild, feasible, low-cost all-solid-state Schottky junction synthesis method to improve pollutants' photocatalytic ability. [ABSTRACT FROM AUTHOR]

• Ultrathin, porous and vacancy-rich CoAl-LDHs nanosheets were prepared by exfoliation strategy. • 2D/2D CoAl-LDHs/Ti 3 C 2 T x hybrids were synthesized via electrostatic assembly process. • Electronic and optical properties were calculated based on density functional theory. • CoAl-LDHs/Ti 3 C 2 T x hybrids exhibited high visible-light photodegradation of antibiotic. • Synergistic effect between CoAl-LDHs and Ti 3 C 2 T x endowed the excellent photocatalytic activity. The layered double hydroxides (LDHs) are potential non-noble metal photocatalysts. Unfortunately, the intrinsic activity of bulk LDHs is relatively low, which limits their use. Herein, the ultrathin, porous and vacancy-rich CoAl-LDHs nanosheets were prepared by exfoliation strategy. Then, they were assembled with the early transition-metal carbides nanosheets (MXenes, Ti 3 C 2 T x) to afford a hybrid 2D/2D CoAl-LDHs/Ti 3 C 2 T x photocatalyst via electrostatic assembly process. The experiments indicated that the CoAl-LDHs/Ti 3 C 2 T x hybrids performed an excellent visible-light photocatalytic activity for tetracycline hydrochloride (96.67 %) degradation. Diversified characterization techniques (SEM, TEM, AFM, N 2 adsorption-desorption analysis, XRD, FTIR, UV–vis DRS, photoelectrochemical test) and density functional theory calculations (electronic and optical properties) have indicated that such excellent photocatalytic activity was ascribed to the synergy and the Schottky heterojunction formation between CoAl-LDHs nanosheets and Ti 3 C 2 T x nanosheets, which possessed markedly visible-light absorption, high specific surface area, rapid electrons transfer and depressed electron-hole pairs recombination. [ABSTRACT FROM AUTHOR]

• In-situ growth of graphene on ZnO surface by CVD method. • Intimate interfacial contact is beneficial to the charge transfer. • Graphene can effectively trap the photogenerated electrons from ZnO. • Photothermal effect of graphene contributed to the performance enhancement. Intimate interfacial contact between semiconductor photocatalysts and cocatalysts is important for the transfer and separation of photogenerated charge carriers. Herein, few-layer graphene, as an efficient cocatalyst, was in-situ deposited on the surface of ZnO. The composite demonstrated improved photocatalytic CO 2 reduction performance than pristine ZnO, ascribing to the intimate interfacial contact and Schottky junction between ZnO and graphene. Meanwhile, photothermal effect of graphene and π-π conjugation interaction between graphene and CO 2 molecules also contributed to the performance enhancement. This work not only provides a feasible approach for the in-situ growth of graphene, but also develops an efficient photocatalyst for CO 2 reduction. [ABSTRACT FROM AUTHOR]

Photo-responsive oxidase-like nanozymes are attractive and highly desirable because they can directly activate O 2 instead of using unstable and destructive H 2 O 2 as oxidant and their activities are photo-switchable by turning light on or off. However, their practical applications are confronted with challenges such low photocatalytic efficiencies. Regulation of charge-carriers migration and separation efficiency is an efficient strategy to enhance photocatalytic performance. Herein, Au@NH 2 -MIL-125(Ti) nanocomposite was constructed by loading Au nanoparticles on the NH 2 -MIL-125(Ti) semiconductor for enhanced photocatalytic activity and explored as a photo-responsive oxidase-like mimic. Its oxidase-mimicking activity is about 3 times higher than that of the pristine NH 2 -MIL-125(Ti) towards colorimetric substrate 3,3′,5,5′-tetramethylbenzidine (TMB) under light irradiation, probably due to the formation of Schottky barrier at the junction between the NH 2 -MIL-125(Ti) and the Au nanoparticles. The enhanced charge transfer and separation in Au@NH 2 -MIL-125(Ti) are verified by photoluminescence spectroscopy and photoelectrochemical experiments. Meanwhile, kinetic analysis demonstrates that the photo-responsive oxidase-like mimic exhibits lower K m value (0.026 mM) and higher V max (13.56 nM s−1) than the natural horseradish peroxidase (K m = 0.43 mM, V max = 10 nM s−1). Radical trapping experiments assured the ·OH and h+ were the major reactive species in the photocatalytic oxidations. Based on its photo-responsive oxidase-like activity and inhibition effect of cysteine, a green colorimetric platform with high sensitivity and selectivity was developed for cysteine detection, with a good linear relationship (1–10 μM) and a very low detection limit of 0.15 μM. This work may shed light on the development of MOF-based photo-responsive oxidase-like mimics for environmentally benign colorimetric biosensing. Image 1 • Au/NH 2 -MIL-125(Ti) composite was prepared simply. • It showed higher photocatalytic efficiency. • Schottky heterojunction formation improved its photocatalytic activity. • A possible photocatalytic mechanism of TMB oxidation was proposed. [ABSTRACT FROM AUTHOR]

In-situ constructing Schottky junction via anchoring Ni-P alloy onto defect-rich ZnS nanospheres for highly efficient visible-light-driven photocatalytic H 2 production. • A unique Schottky junction composed of Ni-P alloy and defect-rich ZnS nanospheres (Ni-P/DR-ZnS) was in-situ fabricated. • The Ni-P/DR-ZnS nanocomposites displayed excellent photocatalytic H 2 evolution activity and stability under visible light. • The as-formed Schottky junction accelerated the separation and transfer of photogenerated charge carriers. • The transfer mechanism of photogenerated charge over the Ni-P/DR-ZnS was studied in detail. The development of efficient and stable photocatalysts is fundamentally required for sunlight-driven water splitting. Herein, Ni-P alloy is controllably anchored onto the surface of defect-rich ZnS (DR-ZnS) nanospheres through in-situ photodeposition strategy. The optimized Ni-P/DR-ZnS nanocomposite displays superior visible-light photocatalytic H 2 production rate (69.92 μmol h−1), which is about 29 times and 3.6 times higher than that of the bare DR-ZnS and 1 wt% Pt/DR-ZnS, respectively, and a notable apparent quantum yield of 2.4 % at 420 nm. The existence of rich defects endows the DR-ZnS with visible-light absorption capability. The constructed Schottky junction between the Ni-P alloy and DR-ZnS accelerates the transfer of photogenerated electrons from DR-ZnS to Ni-P, thus boosting the photocatalytic performance. Moreover, the charge transfer process and underlying photocatalytic mechanism are unravelled by multiple in-depth characterizations. This research sheds novel light on rationally fabricating high-efficient and low-cost photocatalysts through integrating defect engineering and Schottky junction design. [ABSTRACT FROM AUTHOR]