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Showing papers on "Schottky barrier published in 2022"


Journal ArticleDOI
TL;DR: In this article, a two-step hydrothermal process was used to construct a Schottky/step-scheme heterojunction for photocatalytic hydrogen generation activity, achieving a H2 evolution rate of 356.27μmolg-1h−1.

90 citations


Journal ArticleDOI
TL;DR: In this article , a two-step hydrothermal process was used to construct a Schottky/step-scheme heterojunction for boosting photocatalytic hydrogen generation activity.

80 citations


Journal ArticleDOI
TL;DR: In this article, the authors summarized the advances of typical transition metal oxides (TMOs) in photocatalysis and energy storage, and some promising strategies for improving the performance of TMOs/g-C3N4 were proposed.

79 citations


Journal ArticleDOI
TL;DR: In this paper , the authors summarized the advances of typical transition metal oxides (TMOs) in photocatalysis and energy storage, and some promising strategies for improving the performance of TMOs/g-C3N4 were proposed.

72 citations


Journal ArticleDOI
TL;DR: In this article , the Nb2C MXene-derived ternary photocatalyst was synthesized via one-pot in-situ hydrothermal method for photocatalytic hydrogen (H2) evolution.

71 citations


Journal ArticleDOI
TL;DR: In this paper , the work functions of laser-induced graphene (LIG) were controlled by adjusting the frequency or speed of the laser, and a series of LIG/GaOx Schottky photodetectors were formed.
Abstract: Laser-induced graphene (LIG) is a simple, environmentally friendly, efficient, and less costly method, as well as can form various shapes on a flexible substrate in situ without the use of masks. More importantly, it can tune the work function of LIG easily by changing laser parameters to control the transportation of carriers. In this work, the work functions of LIG were controlled by adjusting the frequency or speed of the laser, and a series of LIG/GaOx Schottky photodetectors were formed. When the work function of the graphene increases, the Fermi energy is shifted below the crossing point of the Π and Π* bands, and then more electrons or holes can be activated to participate in the conduction process, resulting in low resistance. Meanwhile, a large built-in electric field can be formed when using a high work function LIG, which is more beneficial to separate photo-generated carriers. Enabled by the controllable LIG, LIG/GaOx Schottky photodetectors can be modulated to have high photoresponsivity or self-powered characteristics. Our work provides a high-performance photodetector with excellent mechanical flexibility and long-life stability, promising applications in the flexible optoelectronic fields.

69 citations


Journal ArticleDOI
TL;DR: In this paper , a metal-semiconductor BaTiO3@ReS2 Schottky heterostructure is designed and it shows high efficiency on piezo-assisted photocatalytic molecular oxygen activation.
Abstract: The piezo‐assisted photocatalysis system, which can utilize solar energy and mechanical energy simulteneously, is promising but still challenging in the environmental remediation field. In this work, a novel metal–semiconductor BaTiO3@ReS2 Schottky heterostructure is designed and it shows high‐efficiency on piezo‐assisted photocatalytic molecular oxygen activation. By combining experiment and calculation results, the distorted metal‐phase ReS2 nanosheets are found to be closely anchored on the surface of the BaTiO3 nanorods, through interfacial ReO covalent bonds. The Schottky heterostructure not only forms electron‐transfer channels but also exhibits enhanced oxygen activation capacity, which are helpful to produce more superoxide radicals. The polarization field induced by the piezoelectric BaTiO3 can lower the Schottky barrier and thus reduce the transfer resistance of photogenerated electrons directing to the ReS2. As a result of the synergy effect between the two components, the BaTiO3@ReS2 exhibits untrahigh activity for degradation of pollutants with an apparent rate constant of 0.133 min−1 for piezo‐assisted photocatalysis, which is 16.6 and 2.44 times as that of piezocatalysis and photocatalysis, respectively. This performance is higher than most reported BaTiO3‐based piezo‐assisted photocatalysis systems. This work paves the way for the design of high‐efficiency piezo‐assisted photocatalytic materials for environmental remediation through using green energies in nature.

65 citations


Journal ArticleDOI
TL;DR: In this article, the rapid and solvent-free high-energy ball-milling procedure was adopted to modify graphitic carbon nitride (g-C3N4) on a large-scale by phosphorus (P) atom doping and molybdenum phosphide (MoP) decorating.
Abstract: The critical prerequisite for realizing the industrial application of photocatalytic technology lies on developing efficient photocatalyst through reasonable and large-scale modification strategy. Herein, the rapid and solvent-free high-energy ball-milling procedure was adopted to modify graphitic carbon nitride (g-C3N4) on a large-scale by phosphorus (P) atom doping and molybdenum phosphide (MoP) decorating. It is confirmed that P doping can introduce a mid-gap state in the band gap of g-C3N4, broadening the light responsive region and enhancing the electrical conductivity of g-C3N4. The Mo N bond at the interface of P-doped g-C3N4 and MoP acting as electrons “delivery channels” facilitates the charge transfer from P-doped g-C3N4 to MoP, while the Schottky barrier promotes the separation of photocarriers. As a result, the optimized P-doped g-C3N4/MoP photocatalyst performs an improved H2 evolution rate of 4917.83 μmol·g−1·h−1 and a favorable H2 production stability. This work offers a replicable prototype on adopting high-energy ball-milling to modify photocatalyst.

61 citations


Journal ArticleDOI
01 Apr 2022
TL;DR: In this article , the rapid and solvent-free high-energy ball-milling procedure was adopted to modify graphitic carbon nitride (g-C3N4) on a large-scale by phosphorus (P) atom doping and molybdenum phosphide (MoP) decorating.
Abstract: The critical prerequisite for realizing the industrial application of photocatalytic technology lies on developing efficient photocatalyst through reasonable and large-scale modification strategy. Herein, the rapid and solvent-free high-energy ball-milling procedure was adopted to modify graphitic carbon nitride (g-C3N4) on a large-scale by phosphorus (P) atom doping and molybdenum phosphide (MoP) decorating. It is confirmed that P doping can introduce a mid-gap state in the band gap of g-C3N4, broadening the light responsive region and enhancing the electrical conductivity of g-C3N4. The MoN bond at the interface of P-doped g-C3N4 and MoP acting as electrons “delivery channels” facilitates the charge transfer from P-doped g-C3N4 to MoP, while the Schottky barrier promotes the separation of photocarriers. As a result, the optimized P-doped g-C3N4/MoP photocatalyst performs an improved H2 evolution rate of 4917.83 μmol·g−1·h−1 and a favorable H2 production stability. This work offers a replicable prototype on adopting high-energy ball-milling to modify photocatalyst.

61 citations


Journal ArticleDOI
TL;DR: In this paper , a 3C2 MXene composite was obtained using a simple hydrothermal method for increasing the photocatalytic degradation ability of methylene blue (MB).

45 citations



Journal ArticleDOI
TL;DR: In this paper , a review of the state-of-the-art research on self-powered solar-blind photodetectors based on Ga2O3 is presented.

Journal ArticleDOI
TL;DR: In this paper , a simple sonication method was used to construct a Ti3C2Tx-ZnO nanosheet hybrid, which exhibited a short recovery time (10 s) under UV (ultraviolet) illumination, a short response time (22 s), a high sensitivity (367.63% to 20 ppm NO2) and selectivity.
Abstract: Recently, Ti3C2Tx MXenes have begun to receive attention in the field of gas sensors owing to their characteristics of high conductivity and abundant surface functional groups. However, Ti3C2Tx-based gas sensors still suffer from the drawbacks of low sensitivity and sluggish response/recovery speed towards target gases, limiting their development in further applications. In this work, Ti3C2Tx-ZnO nanosheet hybrids were fabricated through a simple sonication method. The Ti3C2Tx-ZnO nanosheet hybrids exhibited a short recovery time (10 s) under UV (ultraviolet) illumination, a short response time (22 s), a high sensitivity (367.63% to 20 ppm NO2) and selectivity. Furthermore, the Ti3C2Tx-ZnO sensor has prominent anti-humidity properties, as well as superior reproducibility in multiple tests. The abundant active sites in the Ti3C2Tx-ZnO nanosheet hybrids, including surface groups (-F, -OH, -O) of Ti3C2Tx and oxygen vacancies of ZnO, the formation of Schottky barriers between Ti3C2Tx and ZnO nanosheets and the rich photogenerated charge carriers of ZnO under UV illumination, together result in excellent gas-sensing performance. Density functional theory calculations have been further employed to explore the sensing performance of Ti3C2Tx and ZnO nanosheets, showing strong interactions existing between the NO2 and ZnO nanosheets. The main adsorption sites for NO2 were present on the ZnO nanosheets, while the Ti3C2Tx played the role of the conductive path to accelerate the transformation of charge carriers. Our work can provide an effective way for improving the gas-sensing performances of Ti3C2Tx-based gas sensors.

Journal ArticleDOI
TL;DR: In this article , surface modification with LiF, Se, and polyethylenimine ethoxylated (PEIE) electrodes was used to tune the window of MXene's work function.
Abstract: Tunable work function has a high profile for the MXene‐based optoelectronic devices, and surface modification provides the huge potential to shift its Fermi level and modulate the work function. In this work, the window of MXene's work function is engineered from 4.55 to 5.25 eV by surface modification with LiF, Se, and polyethylenimine ethoxylated (PEIE). The vertical p‐CsCu2I3/n‐Ca2Nb3‐xTaxO10 junction photodetectors are constructed on the basis of the above surface‐modified MXenes, which changes the Schottky barrier between n‐Ca2Nb3‐xTaxO10 and the electrodes. In particular, the rectification effect is significantly enhanced by utilizing PEIE‐decorated MXene electrodes, resulting in a high rectification ratio of 16 136 and improved UV responsivity of 81.3 A W–1. Such high‐performance devices based on MXenes electrodes are compatible with the standard clean room fabrication process, realizing large‐scale flexible UV detectors that maintain 80% of the original current after 5000 times bending. Meanwhile, a photodetector array stimulated with UV of different wavelengths is constructed to reveal its potential for image sensing. Finally, functional “AND” and “OR” optoelectronic logic gates are developed for UV communication using Au/CsCu2I3/Ca2Nb3‐xTaxO10/MXene–PEIE photodetectors, enriching the application of MXene‐based optoelectronic devices. This work on tuning MXene work function via surface modification demonstrates that MXene is a promising candidate for future optoelectronics.

Journal ArticleDOI
TL;DR: In this article , the ZnIn2S4 (ZIS)-NiSe2 S-scheme heterojunctions anchored on Ti3C2 MXene (MX) with multiple internal electric fields were rationally fabricated for effective photocatalytic H2 generation.

Journal ArticleDOI
TL;DR: In this paper , the authors reported the synthesis of ZnIn2S4 nanoparticles on bulk WC by a facile hydrothermal process to construct novel and highly efficient noble metal-free Schottky junction heterojunction photocatalysts.

Journal ArticleDOI
TL;DR: In this article , a series of noble-metal-free MoP/In2S3 Schottky heterojunction photocatalysts were synthesized through two-step synthesis.


Journal ArticleDOI
TL;DR: In this article , the authors highlighted the current literature and explained the synthesis, structure, morphology, modification strategies, and photocatalytic applications of emerging BiPO 4 -based photocatalyst.

Journal ArticleDOI
TL;DR: In this article , surface modification with LiF, Se, and polyethylenimine ethoxylated (PEIE) electrodes was used to tune the window of MXene's work function.
Abstract: Tunable work function has a high profile for the MXene-based optoelectronic devices, and surface modification provides the huge potential to shift its Fermi level and modulate the work function. In this work, the window of MXene's work function is engineered from 4.55 to 5.25 eV by surface modification with LiF, Se, and polyethylenimine ethoxylated (PEIE). The vertical p-CsCu2I3/n-Ca2Nb3-xTaxO10 junction photodetectors are constructed on the basis of the above surface-modified MXenes, which changes the Schottky barrier between n-Ca2Nb3-xTaxO10 and the electrodes. In particular, the rectification effect is significantly enhanced by utilizing PEIE-decorated MXene electrodes, resulting in a high rectification ratio of 16 136 and improved UV responsivity of 81.3 A W–1. Such high-performance devices based on MXenes electrodes are compatible with the standard clean room fabrication process, realizing large-scale flexible UV detectors that maintain 80% of the original current after 5000 times bending. Meanwhile, a photodetector array stimulated with UV of different wavelengths is constructed to reveal its potential for image sensing. Finally, functional “AND” and “OR” optoelectronic logic gates are developed for UV communication using Au/CsCu2I3/Ca2Nb3-xTaxO10/MXene–PEIE photodetectors, enriching the application of MXene-based optoelectronic devices. This work on tuning MXene work function via surface modification demonstrates that MXene is a promising candidate for future optoelectronics.

Journal ArticleDOI
TL;DR: In this article , the impact of Fermi level pinning (FLP) on 2D semiconductor devices has been investigated by exploring various origins responsible for the FLP, effects of FLP on two-dimensional device performances, and methods for improving metallic contact to 2D materials.
Abstract: Motivated by the high expectation for efficient electrostatic modulation of charge transport at very low voltages, atomically thin 2D materials with a range of bandgaps are investigated extensively for use in future semiconductor devices. However, researchers face formidable challenges in 2D device processing mainly originated from the out-of-plane van der Waals (vdW) structure of ultrathin 2D materials. As major challenges, untunable Schottky barrier height and the corresponding strong Fermi level pinning (FLP) at metal interfaces are observed unexpectedly with 2D vdW materials, giving rise to unmodulated semiconductor polarity, high contact resistance, and lowered device mobility. Here, FLP observed from recently developed 2D semiconductor devices is addressed differently from those observed from conventional semiconductor devices. It is understood that the observed FLP is attributed to inefficient doping into 2D materials, vdW gap present at the metal interface, and hybridized compounds formed under contacting metals. To provide readers with practical guidelines for the design of 2D devices, the impact of FLP occurring in 2D semiconductor devices is further reviewed by exploring various origins responsible for the FLP, effects of FLP on 2D device performances, and methods for improving metallic contact to 2D materials.

Journal ArticleDOI
TL;DR: In this paper , the authors tune Schottky barriers over Ni/S vacancy-rich Mn0.3Cd0.7S (Ni/MCS-s) composites prepared by self-assembly and photochemical method.
Abstract: Although Schottky barriers at the interface of metal/semiconductor help electron/hole separation in photocatalysis, they also limit the migration of electrons across the interface. Herein, we tune Schottky barriers over Ni/S vacancy-rich Mn0.3Cd0.7S (Ni/MCS-s) composites prepared by self-assembly and photochemical method. The Ni/MCS-s heterostructures exhibits superior hydrogen production activity up to 164.1 mmol/h/g in simulated seawater (3.5 wt% NaCl), which is 68 and 5 times higher than MCS-s and 1 wt% Pt/MCS-s, respectively. The apparent quantum yield reached 60.4% at 420 nm. The excellent photocatalytic performance of Ni/MCS-s results from the coupling of plasmonic Ni and S vacancies, which can effectively lower Schottky barrier and enhance hot electrons across the interface for photocatalytic process. Moreover, the Ni layer effectively prevents the catalyst from being corroded in seawater. This work provides a feasible strategy for designing efficient photocatalysts for solar energy conversion in seawater.

Journal ArticleDOI
TL;DR: In this paper , the authors highlight the recent advances of the adopted synthetic routes to develop MXene-derived TiO 2 and MXene/TiO 2 based nanocomposite.
Abstract: MXenes have grabbed considerable research attention in photocatalytic field owing to their regular planer structure, elemental composition, excellent metal conductivity, surface termination groups and abundant derivatives. MXene-derived and based materials deliver motivation for fabrication of novel photocatalysts with optimum activity, and long term stability. Meanwhile, TiO 2 being the most extensively studied photocatalyst for solar light driven water splitting and environmental remediation, owing to its noble photocatalytic activity, low cost, nontoxicity, and copious availability. Nevertheless, the major drawbacks of TiO 2 based systems are its ultra-wide band gap and rapid recombination of photoinduced charge carriers. In this context, MXene have been rigorously explored for the modification of TiO 2 which includes the MXene derived TiO 2 (in-situ derived TiO 2 from MXene) and MXene/TiO 2 based nanocomposite (externally added TiO 2 with MXene) for easy channelization of electrons owing to the metal-semiconductor contact where MXene can behave as a co-catalyst or support by enhancing the overall activity. Although a few reviews have been published highlighting the synthesis, inherent properties and applications in various fields, but this particular review highlights the recent advances of the adopted synthetic routes to develop MXene-derived TiO 2 and MXene/TiO 2 based nanocomposite, explaining the mechanism of charge carrier separation due to the formation of schottky junction at the interface of electrically conductive Ti 3 C 2 and optically active TiO 2 for achieving outstanding photocatalytic hydrogen (H 2 ) evolution and pollutant degradation. Furthermore, the future challenges including the materials design process and to improve the overall activity for the promotion of MXenes derivative and allied materials has been proposed with correlating the structural features and activity. This review summarizes the synthetic technique and morphological features of MXene derived TiO 2 and MXene/TiO 2 based nanocomposites towards photocatalytic H 2 production and pollutant degradations. • Recent developments of MXene derived and MXene based photocatalyst is summarized. • Novel MXene/TiO 2 nanocomposites suitability towards energy and environmental application. • Respective role of Ti 3 C 2 and TiO 2 is studied for photocatalytic H 2 generation and dye degradation. • Challenges and future roadmaps regarding these class of nanohybrids are outlined.

Journal ArticleDOI
TL;DR: In this article , the authors used exfoliated montmorillonite (MMTex) to efficiently inhibit oxidation of Ti3C2 during the hydrothermal synthesis process, simultaneously weakening the adverse effects of surface-F terminations and achieving surface oxygen functionalization.

Journal ArticleDOI
TL;DR: In this article , a self-powered photodetector based on the Schottky junction of Au NPs, which can detect 325 nm light with the power density of 68 nW/cm2, by using pyro-phototronic effect enhanced by localized surface plasmon resonance (LSPR).

Journal ArticleDOI
TL;DR: In this paper , a chemical reduction method was performed to combine bimetallic Ag-Pd alloy nanoparticles (NPs) with spherical-like ZnIn 2 S 4 (ZIS).

Journal ArticleDOI
TL;DR: In this paper, the authors proposed the concept of electron-welcome zone, where the point-to-point contact can be formed at the interface, thus providing continuous electron transport channels.
Abstract: Photocatalysis has been facing challenging problems especially the inefficient photocarriers transfer at the interfaces. Here, based on Ksp difference, we prepare the sequential heterojunction of CoS/CdS/CuS via sequential cation exchange strategy, and propose the concept of "electron-welcome zone", where the point-to-point contact can be formed at the interface, thus providing continuous electron transport channels. HAADF-STEM EDS line test indicates the formation of designed structures, and the p/n junction is confirmed by band structure and Mott-Schottky analysis. Theoretical calculation indicates that CoS reduces the Gibbs free energy of the reaction. TRPL spectra show that the existence of "electron welcome zone" greatly improves the lifetime of electrons. This sequential structure enable the optimal H2 production rate to reach 123.2 mmol g−1 h−1 with AQE of 45.6%, which is among the highest values of CdS-based photocatalysts. This work opens new way to efficient photogenerated carrier transfer channel for solar-energy conversion.

Journal ArticleDOI
TL;DR: In this paper , the authors summarize the recent progress in the rational design and fabrication of heterojunction nanomedicine, such as semiconductor-semiconductor heterojunctions (including type I, type II, type III, PN, and Z-scheme junctions).
Abstract: Exogenous stimulation catalytic therapy has received enormous attention as it holds great promise to address global medical issues. However, the therapeutic effect of catalytic therapy is seriously restricted by the fast charge recombination and the limited utilization of exogenous stimulation by catalysts. In the past few decades, many strategies have been developed to overcome the above serious drawbacks, among which heterojunctions are the most widely used and promising strategy. This review attempts to summarize the recent progress in the rational design and fabrication of heterojunction nanomedicine, such as semiconductor–semiconductor heterojunctions (including type I, type II, type III, PN, and Z–scheme junctions) and semiconductor–metal heterojunctions (including Schottky, Ohmic, and localized surface plasmon resonance–mediated junctions). The catalytic mechanisms and properties of the above junction systems are also discussed in relation to biomedical applications, especially cancer treatment and sterilization. This review concludes with a summary of the challenges and some perspectives on future directions in this exciting and still evolving field of research.

Journal ArticleDOI
TL;DR: In this paper , a dual-functional composite catalyst for photocatalytic hydrogen evolution and benzaldehyde production was proposed, and a new strategy for preventing the photogenerated electrons and holes from recombining by constructing a 0D/2D heterojunction with increased Schottky barrier (SB) sites.
Abstract: Abstract Converting water into hydrogen fuel and oxidizing benzyl alcohol to benzaldehyde simultaneously under visible light illumination is of great significance, but the fast recombination of photogenerated carriers in photocatalysts seriously decreases the conversion efficiency. Herein, a novel dual-functional 0D Cd 0.5 Zn 0.5 S/2D Ti 3 C 2 hybrid was fabricated by a solvothermally in-situ generated assembling method. The Cd 0.5 Zn 0.5 S nano-spheres with a fluffy surface completely and uniformly covered the ultrathin Ti 3 C 2 nanosheets, leading to the increased Schottky barrier (SB) sites due to a large contact area, which could accelerate the electron-hole separation and improve the light utilization. The optimized Cd 0.5 Zn 0.5 S/Ti 3 C 2 hybrid simultaneously presents a hydrogen evolution rate of 5.3 mmol/(g·h) and a benzaldehyde production rate of 29.3 mmol/(g·h), which are ∼3.2 and 2 times higher than those of pristine Cd 0.5 Zn 0.5 S, respectively. Both the multiple experimental measurements and the density functional theory (DFT) calculations further demonstrate the tight connection between Cd 0.5 Zn 0.5 S and Ti 3 C 2 , formation of Schottky junction, and efficient photogenerated electron—hole separation. This paper suggests a dual-functional composite catalyst for photocatalytic hydrogen evolution and benzaldehyde production, and provides a new strategy for preventing the photogenerated electrons and holes from recombining by constructing a 0D/2D heterojunction with increased SB sites.

Journal ArticleDOI
TL;DR: In this paper , a clean van der Waals contact is demonstrated, wherein a metallic 2D material, chlorine-doped SnSe2 (Cl-SnSe2), is used as the high-work-function contact, providing an interface that is free of defects and Fermi-level pinning.
Abstract: Precise control over the polarity of transistors is a key necessity for the construction of complementary metal–oxide–semiconductor circuits. However, the polarity control of 2D transistors remains a challenge because of the lack of a high‐work‐function electrode that completely eliminates Fermi‐level pinning at metal–semiconductor interfaces. Here, a creation of clean van der Waals contacts is demonstrated, wherein a metallic 2D material, chlorine‐doped SnSe2 (Cl–SnSe2), is used as the high‐work‐function contact, providing an interface that is free of defects and Fermi‐level pinning. Such clean contacts made from Cl–SnSe2 can pose nearly ideal Schottky barrier heights, following the Schottky–Mott limit and thus permitting polarity‐controllable transistors. With the integration of Cl–SnSe2 as contacts, WSe2 transistors exhibit pronounced p‐type characteristics, which are distinctly different from those of the devices with evaporated metal contacts, where n‐type transport is observed. Finally, this ability to control the polarity enables the fabrication of functional logic gates and circuits, including inverter, NAND, and NOR.