Work Function Difference Research Articles

Interfacial modification of GO-FePt hybrid film leads to giant ultrafast optical nonlinearity

Excellent optical nonlinearity is highly promising for the development of multifunctional ultrafast photonics techniques and integrated optoelectronic devices. However, existing numerous optical materials commonly suffer from several challenges, such as bad functional integration, slow response speed, and weak optical nonlinearity thus severely hindering their extensive applications. Here, we first engineer new scalable graphene oxide (GO)-FePt films by chemistry induced self-assembly and then demonstrate the enhanced ultrafast optical nonlinearity by resorting to their interfacial modifications. It is found that the FePt magnetic nanoparticles (NPs) are easily assembled on the surface of the GO by exchanging the surface ligands of the former with evaporated solvent, leading to good water solubility and super-paramagnetism. The femtosecond Z-scan test results show that both the nonlinear saturation absorption and optical Kerr refraction of the pure GO are subjected to reversion once the FePt NPs are introduced. More importantly, we can greatly enhance the ultrafast nonlinear optics response of as-prepared GO-FePt hybrid film by promoting the concentration of magnetic NPs. In addition, the associated optical nonlinearity can be further boosted with femtosecond vectorial beams excitation instead of the linearly polarized one. In principle, the enhanced optical nonlinearity may arise from direct metal-to-semiconductor interfacial charge transfer transition (DICTT) related to the difference in work function and Fermi level together with complicated interaction between the vectorial light fields and the hybrid films. The GO-based magnetic hybrid films with giant ultrafast optical nonlinearity have potential wide-ranging applications in integrated optoelectronics, ultrafast nanophotonics, opto-magnetic storage, and beyond.

Regulating the Spin State of Metal and Metal Carbide Heterojunctions for Efficient Oxygen Evolution.

Developing high-performance electrocatalysts for oxygen evolution reaction (OER) is of importance for improving the overall efficiency of water splitting. Herein, the CoFe/(CoxFe1-x)3Mo3C heterojunction is purposely designed as an OER catalyst, which displays a low overpotential of 293 mV for affording a current density of 10 mA cm-2 and a small Tafel slope of 48 mV/dec. Various characterization results demonstrate that the significant work-function difference between CoFe and (CoxFe1-x)3Mo3C can induce interfacial charge redistribution, which results in the formation of Co and Fe sites with a high-spin state, thus stimulating the surface phase reconstruction of CoFe/(CoxFe1-x)3Mo3C to corresponding active oxyhydroxide. Meanwhile, the electrochemical leaching of Mo ions from the initial structure can contribute to the formation of defective sites, further benefiting OH- adsorption and surface oxidation. Moreover, the remaining CoFe can accelerate electron migration during the electrocatalytic process. This study presents new insights into constructing efficient OER electrocatalysts with an optimized spin-state configuration via interfacial engineering.

Dual in-plane/out-of-plane Ni2P-BP/MoS2 Mott-Schottky heterostructure for highly efficient hydrogen production

A catalyst innovation with the aim of developing noble-metal-free substitutes is one key aspect for future sustainable hydrogen energy deployment. Herein, we fabricated a dual in-plane/out-of-plane Ni2P-black phosphorus (BP)/MoS2 heterostructure through an all-solution process for the hydrogen evolution reaction (HER). The covalently cross-connected MoS2 and metallic Ni2P-BP interfaces benefit the charge transfer in the electrochemical performances via the Mott-Schottky effect. For the HER, the Ni2P-BP/MoS2 heterostructure shows excellent catalytic activity with a low overpotential of 99 mV at 10 mA cm−2 and a small Tafel slope of 97 mV dec−1 in alkaline electrolyte. The first-principle calculations verify that the work function difference at the Mott-Schottky interface favors electron transfer from Ni2P-BP to outer-surface MoS2 to boost the HER process. Therefore, the Ni2P-BP/MoS2 heterostructure presents near-neutral hydrogen adsorption free energy (ΔGH*, −0.0287 eV), indicating superior HER activity beyond the counterparts (MoS2, BP, and Ni2P-BP). This work inspires possibilities for optimizing BP-based composites through multidimensional interface engineering with the goal of achieving highly efficient hydrogen production electrocatalysis.

Enhanced performance of Janus XMSiY2 (X=S, Se; M=Mo, W; and Y=N, P) monolayers for photocatalytic water splitting via strain engineering

In this article, using first-principles calculations, we propose XMSiY2 (X = S, Se; M = Mo, W; and Y=N, P) monolayers as a Janus form of MA2Z4 family and investigate their electronic, spintronic, and photocatalytic properties. The obtained band structures show that XMSiY2 monolayers are semiconductors with bandgaps ranging from 1.21 eV to 2.98 eV. Considering spin-orbit coupling, we observe that broken out-of-plane symmetry in the XMSiY2 structures leads to Rashba spin-splitting at the Γ point and lack of inversion symmetry results in Zeeman spin-splitting at the K point of the valence bands. The monolayers with W atom exhibit larger Zeeman spin-splitting (up to 0.479 eV for SeWSiP2) which indicates that XWSiY2 monolayers are promising materials for spintronic and valleytronic applications. Assisted by the large work function difference (Δ&varphi) between two surfaces of the Janus XMSiY2 monolayers, all the proposed structures satisfy the band alignment requirement for overall water splitting. Benefiting from strong solar absorption, large carrier mobility (up to 104 cm2 V−1 s−1) and huge difference between electron and hole mobilities, XMSiY2 monolayers are predicted to be high performance photocatalysts. Lastly, the effect of biaxial strain on the photocatalytic properties of the proposed monolayers is comprehensively investigated and it is found that compressive strain helps XMSiY2 structures to act as great photocatalysts for overall water splitting in an expanded range of pH. In addition, tensile strain can broaden and intensify the solar light absorption spectrum of XMSiY2 monolayers to achieve high performance photocatalysts.

Correlation Between Nonmetallic Inclusions and Localized Corrosion of a Low‐Nickel Stainless Steel with Cerium Treatment

The localized corrosion induced by different kinds of inclusions in low‐nickel stainless steel is studied through immersion tests and first‐principles calculations. The galvanic corrosion between the steel matrix and different kinds of inclusions occurs in the corrosive environment due to the difference in the electron work function of the steel matrix and inclusions. The electron work function of MnS, CeS, and Ce‐O‐S is smaller than that of the steel matrix, thus, these inclusions first dissolve as the anode. However, the electron work function of cerium‐containing oxides is bigger than that of the steel matrix, and the steel matrix dissolves prior to cerium‐containing oxides. The order of the volume expansion rate of pits induced by inclusions is CeS > Si‐Mn(‐Al)‐O > MnS > Ce‐C‐O‐S > Ce‐Si‐Mn(‐Al)‐O > Ce‐O‐S. For cerium‐containing inclusions, the electron work function of inclusions increases with the increase of the O/Ce ratio and the S/Ce ratio of inclusions. The order of the electron work function of cerium‐containing inclusions is cerium oxides > cerium sulfides > cerium oxysulfide.

VOC Bonding of Heterointerface Boosting Kinetics of Free‐Standing Na5V12O32 Cathode for Ultralong Lifespan Sodium‐Ion Batteries

AbstractThe flexible free‐standing cathodes with high energy density have been challenging toward wearable sodium‐ion batteries (SIBs). Herein, Na5V12O32 nanobelts (NVO‐NBs)‐based heterostructure is fabricated with boosting the sodium‐ion kinetic characteristics to address the challenges. In the heterostructure, the controllable VOC bonds are generated at the interface originating from the chemical conversion of functional groups of the reduced graphene oxides (rGOs) with VO bonding of NVO through interfacial electronic interactions. The interfacial synergistic between the brilliant bonding properties and the inherent formation of a stress field at the heterointerface motivated by work function difference can reduce the Na+ diffusion barrier, facilitate charge transfer, hence accelerates reaction kinetics and electron/ion transport, as well as modifying the electronic structure to realize a cherished adsorption energy of Na+. Therefore, the optimized NVO‐NBs‐based heterostructure exhibits exceptional rate capability (213 mAh g−1 at 0.2 C with 100 mAh g−1 at 10 C) and ultralong cycling stability (95.4%, 3000 cycles at 5 C). This work demonstrates that the controllable heterostructure interface with abundant chemical bonds is an effective approach to exploit potential cathodes for rechargeable batteries.

Unique Contact Point Modification Technique for Boosting the Performance of a Triboelectric Nanogenerator and Its Application in Road Safety Sensing and Detection.

A triboelectric nanogenerator (TENG) is a potential technique that can convert waste kinetic energy to electrical energy by contact separation followed by electrostatic induction. Herein, a unique contact point modification technique has been reviewed carefully via the enlargement of the effective surface area of the tribo layer by using a simple and scalable printing method. In this study, the zinc sulfide (ZnS) nanostructure morphology has been introduced directly on an aluminum electrode (Al) as a tribo positive layer by a modified hydrothermal method and different line patterns directly printed on overhead projector (OHP) transparent sheets by a monochrome laser printer as a tribo negative layer to increase the effective contact area and work-function difference between two tribo layers. This dual parameter results in ∼11 times increment in the open-circuit output voltage (∼420 V) and ∼17 times increment in the short-circuit current density (∼83.33 mA m-2) compared to the normal one. Furthermore, with the proposed surface modification technique, an ultrahigh instantaneous output power density of ∼3.9 W m-2 at a load resistance of 2 MΩ was easily achieved. The direct energy conversion efficiency reached up to 66.67% at 2 MΩ load, which is very high compared to other traditional TENGs. Further, the fabricated TENG demonstrated efficacy in novel road safety sensing applications in hilly areas to control vehicle movement. Therefore, the current idea of surface engineering using a laser printer will be helpful for energy-harvesting enthusiasts to develop more efficient nanogenerators for higher energy conversions.

High performance aqueous asymmetric supercapacitors developed by interfacial engineering wood-derived nanostructured electrodes

Supercapacitors (SCs) are becoming new candidates in the field of sustainable energy supply. Nevertheless, the unsatisfactory energy density due to the narrow voltage window of the supercapacitor is the main barrier to its practical application. Developing appropriate electrode materials to improve the electrochemical performance of SCs and broaden the operating voltage of supercapacitors are imperative. Herein, compatible interfacial engineering wood-derived nanostructured electrodes for aqueous asymmetric supercapacitors (AASCs) are demonstrated. The 3D carbonized wood matrix serves as a high specific surface area current collector and a porous host for the high capacitive active substance, which is composed of manganese dioxide (MnO2) nanowires and polyaniline (PANI) nanoparticles grown uniformly on the porous wall of aligned microchannels (CW@MnO2 and CW@PANI). The resulting electrochemical exchange reactive sites enable the positive electrode to deliver a high areal capacitance of 729 mF cm−2 at 1 mA cm−2 (369 F g−1 at 0.5 A g−1). The negative electrode delivers a high areal capacitance of 1721 mF cm−2 at 1 mA cm−2 (848 F g−1 at 0.5 A g−1). The areal capacitance of two electrodes is superior to most reported supercapacitor electrodes. Additionally, the assembled CW@MnO2//CW@PANI AASC achieves a desirable energy density (170.84 μWh cm−2 at a power density of 0.5 mW cm−2) because a considerable work function difference between electrodes achieved a 2 V wide voltage window. The results of this study provide a critical benchmark and optimistic incentives to adopt natural hierarchical structures to enhance the performance of new-generation energy-related systems.

Ferroelectric Modulation in Flexible Lead-Free Perovskite Schottky Direct-Current Nanogenerator for Capsule-Like Magnetic Suspension Sensor.

The tribovoltaic nanogenerator (TVNG), a promising semiconductor energy technology, displays outstanding advantages such as low matching impedance and continuous direct-current output. However, the lack of controllable and stable performance modulation strategies is still a major bottleneck that impedes further practical applications of TVNG. Herein, by leveraging the ferroelectricity-enhanced mechanism and the control of interfacial energy band bending, a lead-free perovskite-based (3,3-difluorocyclobutylammonium)2 CuCl4 ((DF-CBA)2 CuCl4 )/Al Schottky junction TVNG is constructed. The multiaxial ferroelectricity of (DF-CBA)2 CuCl4 enables an excellent surface charge modulating capacity, realizing a high work function regulation of ≈0.7eV and over 15-fold current regulation (from 6 to 93µA) via an electrical poling control. The controllable electrical poling leads to elevated work function difference between the Al electrode and (DF-CBA)2 CuCl4 compared to traditional semiconductors and halide perovskites, which creates a stronger built-in electric field at the Schottky interface to enhance the electrical output. This TVNG device exhibits outstanding flexibility and long-term stability (>20000 cycles) that can endure extreme mechanical deformations, and can also be used in a capsule-like magnetic suspension device capable of detecting vibration and weights of different objects as well as harvesting energy from human motions and water waves.

Improved ferroelectric and endurance properties of Hf0.5Zr0.5O2 thin films by a replacement indium-tin-oxide top electrode process

The ferroelectricity in HfO2-based thin films offers a potential alternative to non-volatile memories and logic devices. Special top electrodes such as nitride metal serving as a mechanical capping layer are used to induce the ferroelectricity in HfO2, which hinders the extensive application of HfO2 ferroelectrics. Indium-tin-oxide (ITO) is a transparent, highly conductive electrode or semiconductor, widely used in microelectronics. Here, we comprehensively investigated the impact of ITO electrodes on the ferroelectric polarization and endurance properties of Hf0.5Zr0.5O2 (HZO) thin films. The remnant polarization (2P r) of ∼23.6 μC cm−2 was obtained for the ITO#/HZO/TiN capacitors with an electrode-replacement technique. The relatively enlarged coercive field of ±1.25 MV cm−1 was observed in the ITO/HZO/TiN capacitors compared with TiN/HZO/TiN structures (±0.94 MV cm−1). This might be owing to the work function difference between top ITO and bottom TiN electrodes, as well as the depletion effect of the ITO interface. Furthermore, stable endurance characteristics after 108 cycles were obtained in the ITO#/HZO/TiN capacitors. This work provides a new strategy to obtain excellent ferroelectricity and good reliability in HfO2-based ferroelectric thin film integration with other oxide electrodes.

Highly Reactive Crystalline (001) Facet of BiI3 Hexagonal Nanoplates for Visible Light Photodetectors

A simple and facile solution phase synthesis of large-scale, micro-to-nanometer sized bismuth triiodide (BiI3) single crystalline hexagonal plates is reported. It is demonstrated that under optimized conditions the reactions result in dominant exposed (001) facets. Because of the large size, high surface-to-volume ratio, and thickness, BiI3 nanoplatelets are attractive as visible light photodetectors. At 1 V bias, the photoresponsivity is 0.87 A W–1; the specific detectivity is 4.8 × 1012 jones with a response rise time of 1 s and a fall time of 0.97 s. The Kelvin probe force microscope images revealed that the surface potential difference across the junction was 42.5 mV, which is attributed to the work function difference between the sample and substrate. The results of this study indicate that single hexagonal platelets of BiI3 are very promising for visible light photodetector applications.

An ultrafast H* migration channel and oxidation activity driven by multifunctional Co atoms on twin Co0.01Mn0.29Cd0.7S homojunction surface for photocatalytic overall water splitting

Low kinetics of water dissociation, unfavorable hydrogen adsorption, and high water-oxidation barriers restrict the photocatalytic overall water splitting (OWS) efficiency over sulfides. Herein, multifunctional Co atoms are doped on the twin Mn0.3Cd0.7S homojunction surface for efficient photocatalytic hydrogen (H2) and oxygen (O2) evolution. An ultrafast hydrogen atom (H*) migration channel bridging the water dissociation/H2 evolution step is established between cubic-S and hexagonal-S sites by introducing Co atoms, facilitating the HER kinetics. Specifically, Co atoms regulate the electron properties of neighboring S atoms and weaken their charge accumulation, which promotes cubic-S sites to capture sufficient H* from the water dissociation zone and accelerates hexagonal-S sites to release H2 through the H* migration channel. Meanwhile, unsaturated Co atoms on the cubic phase as oxygen evolution reaction (OER) sites promote water deprotonation and optimize the kinetics of the rate-determining step to form OOH* intermediate, enhancing water oxidation activity. Co atoms strengthen the internal electric field of the homojunction and local polarized electric field by increasing the work function difference between the two phases and introducing the high spin polarization, inhibiting the bulk and surface recombination of photogenerated carriers. The Co0.01Mn0.29Cd0.7S exhibits visible-light-driven H2 and O2 evolution rates of 443.12 and 219.67 μmol g−1 h−1, about 50 times that of the Mn0.3Cd0.7S. This work provides some guidance for the design of homojunction photocatalysts with efficient OWS performance.

Performance Analysis of Multi-Channel-Multi-Gate-Based Junctionless Field Effect Transistor

In this paper, a multi-gate junctionless field-effect transistor with a quad gate and multiple channels has been proposed and thoroughly simulated. The proposed device offers a lower I off current of 4.34 × 10−19 A, an I on current of 4.17 × 10−06 A with an I on/I off current ratio of 9.65 × 1012, a threshold voltage of 0.86 V, a transconductance of 5 × 10−05 S, a drain-induced barrier lowering (DIBL) of 22 mV/V, and a subthreshold slope (SS) of 61.51 mV/dec. The visual contour plots of the device are also included in this study to understand the working mechanism. The larger tunneling width between the channel drain and barrier height between the source–channel interface exhibits a lower leakage current and better performance. The performance of the proposed device is also studied when the work function between the semiconductor and gate material is altered. The work function difference improves the performance metrics. Aside from that, the effects of temperature variation on the device's performance characteristics are also being studied. When the temperature varies by 33% the threshold voltage of the proposed device drops by only 7% which shows a minimum variation in the proposed device. The results obtained from the proposed device exhibit the potential of using multi-gate multi-channel junctionless field effect transistor (MCMG) device in low-power logic circuits and memory devices.

Constructing Built‐in Electric Field in Heterogeneous Nanowire Arrays for Efficient Overall Water Electrolysis

AbstractEfficient bifunctional electrocatalysts for hydrogen and oxygen evolution reactions are key to water electrolysis. Herein, we report a built‐in electric field (BEF) strategy to fabricate heterogeneous nickel phosphide‐cobalt nanowire arrays grown on carbon fiber paper (Ni2P‐CoCH/CFP) with large work function difference (ΔΦ) as bifunctional electrocatalysts for overall water splitting. Impressively, Ni2P‐CoCH/CFP exhibits a remarkable catalytic activity for hydrogen and oxygen evolution reactions to obtain 10 mA cm−2, respectively. Moreover, the assembled lab‐scale electrolyzer driven by an AAA battery delivers excellent stability after 50 h electrocatalysis with a 100 % faradic efficiency. Computational calculations combining with experiments reveal the interface‐induced electric field effect facilitates asymmetrical charge distributions, thereby regulating the adsorption/desorption of the intermediates during reactions. This work offers an avenue to rationally design high‐performance heterogeneous electrocatalysts.

Constructing Built-in Electric Field in Heterogeneous Nanowire Arrays for Efficient Overall Water Electrolysis.

Efficient bifunctional electrocatalysts for hydrogen and oxygen evolution reactions are key to water electrolysis. Herein, we report a built-in electric field (BEF) strategy to fabricate heterogeneous nickel phosphide-cobalt nanowire arrays grown on carbon fiber paper (Ni2 P-CoCH/CFP) with large work function difference (ΔΦ) as bifunctional electrocatalysts for overall water splitting. Impressively, Ni2 P-CoCH/CFP exhibits a remarkable catalytic activity for hydrogen and oxygen evolution reactions to obtain 10 mA cm-2 , respectively. Moreover, the assembled lab-scale electrolyzer driven by an AAA battery delivers excellent stability after 50 h electrocatalysis with a 100 % faradic efficiency. Computational calculations combining with experiments reveal the interface-induced electric field effect facilitates asymmetrical charge distributions, thereby regulating the adsorption/desorption of the intermediates during reactions. This work offers an avenue to rationally design high-performance heterogeneous electrocatalysts.

Effective threshold voltage modulation technique for steep-slope 2D atomic threshold switching field-effect transistor

Two-dimensional (2D) atomic threshold switching field-effect transistors (ATS-FETs), which integrate 2D FET with threshold switching (TS) devices, have garnered attention as part of the subthreshold swing (SS) improvement for next-generation low-power devices. For industrial applications of 2D ATS-FET, it is important to secure the threshold voltage (Vth) modulation technique. Here, Vth engineering is performed by altering the counter electrode (CE) of a TS device, and the electrical performance of the ATS-FET is systematically investigated. The work function difference between the active electrode and CE alters the internal electric field (E-field) formed between these two electrodes. This severely affects the metal ion migration of the active electrode and induces the Vth shift of the ATS-FET. Because the proposed Vth adjusting technique does not affect the channel material, the MoS2 ATS-FET with the proposed technique can shift Vth while maintaining a high on–off ratio of >105 A on average and achieves an ultra-low average SS of ∼10.929 mV/dec. Moreover, the SS variation due to the random interface traps between the channel and gate dielectric is sufficiently suppressed. This study is expected to be a cornerstone for ATS-FET research by offering a compact platform to adjust Vth without deteriorating steep-slope characteristics.

Design of high-performance ion-doped CoP systems for hydrogen evolution: From multi-level screening calculations to experiment

Rational design of high-performance electrocatalysts for hydrogen evolution reaction (HER) is vital for future renewable energy systems. The incorporation of foreign metal ions into catalysts can be an effective approach to optimize its performance. However, there is a lack of systematic theoretical studies to reveal the quantitative relationships at the electronic level. Here, we develop a multi-level screening methodology to search for highly stable and active dopants for CoP catalysts. The density functional theory (DFT) calculations and symbolic regression (SR) were performed to investigate the relationship between the adsorption free energy (ΔGH*) and 10 electronic parameters. The mathematic formulas derived from SR indicate that the difference of work function (ΔΦ) between doped metal and the acceptor plays the most important role in regulating ΔGH*, followed by the d-band center (d-BC) of doped system. The descriptor of HER can be expressed as ΔGH∗=1.59×0.188ΔΦ+dBC+0.120-0.166 with a high determination coefficient (R2 = 0.807). Consistent with the theoretical prediction, experimental results show that the Al-CoP delivers superior electrocatalytic HER activity with a low overpotential of 75 mV to drive a current density of 10 mA cm−2, while the overpotentials for undoped CoP, Mo-CoP, and V-CoP are 206, 134, and 83 mV, respectively. The current work proves that the ΔΦ is the most significant regulatory parameter of ΔGH* for ion-doped electrocatalysts. This finding can drive the discovery of high-performance ion-doped electrocatalysts, which is crucial for electrocatalytic water splitting.

High-threshold-voltage and low-leakage-current of normally-off H-diamond FET with self-aligned Zr/ZrO2 gate

Normally-off field effect transistor (FET) is highly required for the safe and energy-efficient operation of power switching system. The hydrogen-terminated diamond (H-diamond) FET possesses outstanding properties whereas it usually shows normally on operation. In this paper, high-threshold-voltage and low-leakage-current of normally-off H-diamond FET was achieved via ZrO2/Zr gate fabricated by thermal oxidation (TO) with merits of non-pollution and simple process. The normally-off operation owed to the work function difference between Zr and H-diamond and the positive fixed charge of ZrO2. The X-ray photoelectron spectroscopy results reveal the ZrO2/Zr gate structure and the stoichiometric composition of Zr to O (1:2). The high threshold voltage (−2.7 V) and low drain-source leakage current (10−8 mA/mm) may be attributed to the Schottky barrier of Zr/H-diamond. Additionally, the gate leakage is suppressed by TO-ZrO2. The subthreshold swing, on-off current ratio and gate oxide capacitance per square centimeter are 161 mV/dec, 108 and 0.37 μF/cm2, respectively. These performances demonstrate that the ZrO2/Zr/H-diamond FET would provide an alternative approach for low power H-diamond FET.

Electron transfer rules of minerals under pressure informed by machine learning

Electron transfer is the most elementary process in nature, but the existing electron transfer rules are seldom applied to high-pressure situations, such as in the deep Earth. Here we show a deep learning model to obtain the electronegativity of 96 elements under arbitrary pressure, and a regressed unified formula to quantify its relationship with pressure and electronic configuration. The relative work function of minerals is further predicted by electronegativity, presenting a decreasing trend with pressure because of pressure-induced electron delocalization. Using the work function as the case study of electronegativity, it reveals that the driving force behind directional electron transfer results from the enlarged work function difference between compounds with pressure. This well explains the deep high-conductivity anomalies, and helps discover the redox reactivity between widespread Fe(II)-bearing minerals and water during ongoing subduction. Our results give an insight into the fundamental physicochemical properties of elements and their compounds under pressure.

Construction of ZnIn2 S4 /CdS/PdS S-Scheme Heterostructure for Efficient Photocatalytic H2 Production.

It is facing a tremendous challenge to develop the desirable hybrids for photocatalytic H2 generation by integrating the advantages of a single semiconductor. Herein, an all-sulfide ZnIn2 S4 /CdS/PdS heterojunction is constructed for the first time, where CdS and PdS nanoparticles anchor in the spaces of ZnIn2 S4 micro-flowers due to the confinement effects. The morphology engineering can guarantee rapid charge transfer owing to the short carrier migration distances and the luxuriant reactive sites provided by ZnIn2 S4 . The S-scheme mechanism between ZnIn2 S4 and CdS assisted by PdS cocatalyst is testified by in situ irradiated X-ray photoelectron spectroscopy and electron paramagnetic resonance (EPR), where the electrons and holes move in reverse driven by work function difference and built-in electric field at the interfaces. The optimal ZnIn2 S4 /CdS/PdS performs a glaring photocatalytic activity of 191.9µmol h-1 (10mg of catalyst), and the largest AQE (apparent quantum efficiency) can reach a high value of 26.26%. This work may afford progressive tactics to design multifunctional photocatalysts.