High Peak Current Density Research Articles

Pt-Bi on carbon aerogels as efficient electrocatalysts for ethanol oxidation reaction in alkaline medium

Platinum-containing multimetallic catalysts supported on carbon materials have become one of the main choices for direct ethanol fuel cells (DEFCs) due to their high catalytic activity for the ethanol oxidation reaction (EOR). In this study, a platinum-bismuth alloy catalyst (PtBi@CA) with uniform distribution and small particles was provided by a one-step reduction method without the addition of structure directing agents and stabilizers. In the half-cell test, PtBi@CA(50−50) with the smallest crystallite size has high peak current density and pseudo-steady current density of 64.336 mA/cm2 and 0.096 mA/cm2, respectively, which is 11.22 times and 1.85 times the high of the most advanced commercial carbon-supported platinum catalysts (Pt/C). The method is simple and feasible, greatly reduces the amounts of precious metals, and has broad application prospects in the synthesis of anode electrocatalysts for direct ethanol fuel cells.

M1-xSb1-ySδ (M = Ni, Cu, Co) ternary metal sulfides: Emerging candidates for [formula omitted] reduction in bifacial dye-sensitized solar cells

Antimony-based ternary metal sulfides such as Ni9Sb2S8, Cu3SbS3, and CoSbS have been used as counter electrodes (CEs) in bifacial Dye-Sensitized Solar Cells (DSSCs). The electrochemical results show that antimony-based ternary sulfides have the highest peak current density (JPC), lower peak-to-peak separation (EPP) and charge transfer resistance (RCT) than the corresponding binary sulfides. Notably, under front-side illumination, the highest short circuit current (JSC) of 10.19 mA cm−2 is reached for Cu3SbS3, 9.77 mA cm−2 for Ni9Sb2S8 and 10.44 mA cm−2 for CoSbS, all of them are greater than Pt CE. The efficiency of the CoSbS CE is ∼ 97%, Ni9Sb2S8 CE is ∼ 84% and Cu3SbS3 CE is ∼ 66% when normalized with the efficiency of the Pt CE (∼5.54%). The performance of these ternary sulfide CEs is also evaluated for rear-side illumination. This report elucidates the new class of materials that might be used as a potential counter electrode for bifacial DSSCs.

The extended Stӧber method for synthesizing nitrogen-doped porous carbon nanospheres supported Pt nanoparticles towards methanol oxidation in alkaline media

• N -doped porous carbon nanospheres were prepared via the extended Stӧber method. • The NPCs have a high surface area and abundant nitrogen content. • The Pt nanoparticles supported on NPCs showed superior MOR activity and stability. Heteroatom-doped porous carbon materials have emerged as attractive catalyst supports of Pt nanoparticles in the direct methanol fuel cells (DMFCs). Herein, the simple extended Stӧber method towards nitrogen-doped porous carbon nanospheres (NPCs) is reported by polymerizing of 3-aminophenol-formaldehyde (APF) resin spheres. The synthesized NPCs were applied as a carrier for Pt nanoparticles to fabricate the Pt@NPCs catalyst for methanol oxidation. Compared with the commercial Pt/C catalyst, Pt@NPCs showed the larger electrochemically active area (93.6 m 2 g −1 ), higher peak current density (95.91 mA·cm −2 ) and better stability in alkaline media. This improved performance can be attributed to the porous structure of NPCs and nitrogen atoms doped in the carbon matrix increasing the dispersion of the Pt particles on the NPCs catalyst.

Fabrication of 3D graphene anode for improving performance of miniaturized microbial fuel cells.

A three-dimensional graphene (3D GR) grown by chemical vapor deposition method was used as the anode of a miniaturized microbial fuel cell (mini-MFC), which was to be embedded in a 56-μL anode chamber for the formation of a thicker biofilm from Shewanella bacterial culture to promote high efficient extracellular electron transfer. Such 3D GR structure had fewer defects with few layers, and the framework showed significant high REDOX peak current density, high charge storage and low charge transfer resistance. Besides, the electron transport rate of 3D GR electrode was 0.0176s-1, which was about two times faster than that of GR electrode with nickel foam substrate (GR/NF). Benefiting from the macroporous networks, high electron transfer rate and electrocatalytic activity, 3D GR anode facilitated efficient mass transfer and effective electron transport, further forming denser biofilm on the 3D GR. The maximum output voltage and power density of this mini-MFC were 820mV and 23.8mW/m2, which were much higher than those of the GR/NF anode at 590mV and 12.8mW/m2 and the bare NF anode at 450mV and 4.6mW/m2. The study demonstrated that 3D GR can be a promising anode material for improving MFC performance.

Improving peening efficacy through high-amplitude short duration pulsed current

The efficacy of peening treatment depends on the plasticity of the target metal. In this study, the effectiveness of high-amplitude short duration pulsed current in improving the peening efficacy was examined in a process called electropulsing-assisted ultrasonic nanocrystal surface modification (EP-UNSM). During the EP-UNSM process, the target metal, i.e., Ti64, is subjected to simultaneous ultrasonic peening and electropulsing. The high energy pulsed current can generate a critical magnetic field that can induce the transition of the radical pairs formed by dislocations and the pinning obstacles from the singlet state to the triplet state. This leads to higher dislocation mobility and thus higher plasticity for more effective peening treatment. The results show that the sample treated with EP-UNSM had a deeper plastically deformed layer than that for samples subjected to UNSM and continuous current–assisted UNSM (CC-UNSM), and the maximum depth of plastic deformation was obtained when using the highest peak current density. Due to microstructure refinement, work hardening, and dynamic strain aging, the EP-UNSM sample had a 50% higher surface hardness compared with the control sample. Moreover, the compressive residual stresses generated by EP-UNSM were higher in magnitude and greater in depth compared to those generated by traditional UNSM. These results demonstrate that pulsed current can effectively improve the peening efficacy and EP-UNSM is an effective method for strengthening Ti64.

Heterogeneous Pt-Bi hybrid nanoparticle decorated self-standing hollow TiN nanowire as an efficient catalyst for glycerol electrooxidation

The electrochemical oxidation of glycerol is considered as a promising route to generate high value-added products. Rationally tuning the electronic structure of Pt catalysts by supporter and modifier is desirable for promoting the activity and stability of glycerol electrooxidation reaction (GEOR). In this work, we report Pt–Bi hybrid nanoparticles anchored hollow titanium nitride nanowires grew on carbon cloth (Pt1-x-Bix/TiN HNWs/CC (0≤ x ≤ 1)) as a self-supported monolithic electrode for efficient GEOR. Contributed by 3D porous nanotube structure, high corrosion resistance and conductivity of TiN, and strong electronic coupling effect of Pt, Bi, and TiN, the optimized Pt0.95-Bi0.05/TiN HNWs/CC electrode exhibits good catalytic activity and stability for GEOR. It shows a high peak current density of 88.4 mA cm−2 or 306.7 mA mgPt−1 in 0.05 M glycerol +1.0 M KOH solution. After continuous electrolysis for 8 h in 0.05 M glycerol +1.0 M KOH solution at a constant potential of 0.85 V versus reversible hydrogen electrode (vs. RHE), a high glycerol conversion of 87.0%, a moderate selectivity of 36.6% for glyceric acid, and a good stability were achieved, which is superior to other compared electrodes and most of the reported Pt–Bi catalysts.

Highly Textured Zinc Thin Films through Novel Pulsed Electrodeposition Techniques and Their Applications

The electrodeposition of zinc thin films has been widely investigated with extensive applications in corrosion, battery electrodes, photo- and electro-catalysis. Traditionally, the direct current (DC) method of electroplating has been explored in terms of varying current density to obtain changes in morphology, grain size, preferred crystalline orientation, which in turn have significant consequences for properties such as catalysis and corrosion resistance. We have recently demonstrated [1] a novel, additive-free pulsed plating method to control the specific crystalline growth orientations and average grain size of zinc electrodeposited on steel substrates.Specifically, we have observed a transition of the preferential (002) facets at low peak current density (or low duty cycle) to (101) preferring facets at higher peak current density (or high duty cycle) as determined by the analysis of texture coefficients. Further analysis using scanning electron microscopy reveals a transition from the conventional hexagonal-shaped particles of zinc to needle-shaped structures, accompanied by a change in average crystallite size from 33 to 19 nanometers, determined from X-ray diffraction studies. The variation in morphology is also correlated to crystallographic textures through the analysis of texture coefficients and an understanding of crystallization mechanisms occurring during deposition.Herein, we report on an application of these highly textured zinc-coated steel substrates towards corrosion resistance, through accelerated electrochemical testing. Using industry-standard ASTM methods such as Linear Polarization Resistance (LPR), Linear sweep voltammetry (LSV) and electro-impedance spectroscopy (EIS) measurements, we report on preliminary findings of corrosion potential, current and corrosion rates expressed in mm per year as a function of crystalline texture of the zinc thin films.

Cost-Effective Nanoporous Gold Obtained by Dealloying Metastable Precursor, Au33Fe67, Reveals Excellent Methanol Electro-Oxidation Performance

In this study, we report nanoporous gold (NPG) as an economic, efficient, and stable alternative electrocatalyst for methanol electro-oxidation. The said sample was successfully prepared from an Fe-rich metastable Au33Fe67 supersaturated solid solution acting as the precursor, which was formed into ribbons by the phenomenon of rapid solidification using melt-spinning technique. The as-quenched ribbon was then chemically dealloyed in 1 M HCl at 70 °C for different durations of time. A homogeneous, free-standing, and mechanically stable NPG sample was obtained with tunable ligament shape and size. The morphology and composition were characterized by using SEM with EDS, while the structure by XRD. The sample was examined as an electrocatalyst for methanol electro-oxidation profiting off its large surface area; cyclic voltammetry (CV) was the technique employed for electrochemical studies. In a basic solution of methanol and KOH, the sample displays a low peak potential of 0.47 V vs. Ag/AgCl for methanol electro-oxidation with a high peak current density of 0.43 mA/cm2. In addition, it demonstrates outstanding stability and high poisoning tolerance. It is noteworthy that the fabrication process of the NPG sample from start to end was intentionally opted to be sustainable, cost-effective, rapid, and feasible. The usage of critical raw materials was avoided. As a whole, the properties and results put forth by the NPG sample make it an inexpensive, sustainable, and excellent alternative as an electrocatalyst for methanol electro-oxidation.

Quantum hybridization negative differential resistance from non-toxic halide perovskite nanowire heterojunctions and its strain control

While low-dimensional organometal halide perovskites are expected to open up new opportunities for a diverse range of device applications, like in their bulk counterparts, the toxicity of Pb-based halide perovskite materials is a significant concern that hinders their practical use. We recently predicted that lead triiodide (PbI3) columns derived from trimethylsulfonium (TMS) lead triiodide (CH3)3SPbI3 (TMSPbI3) by stripping off TMS ligands should be semimetallic, and additionally ultrahigh negative differential resistance (NDR) can arise from the heterojunction composed of a TMSPbI3 channel sandwiched by PbI3 electrodes. Herein, we computationally explore whether similar material and device characteristics can be obtained from other one-dimensional halide perovskites based on non-Pb metal elements, and in doing so deepen the understanding of their mechanistic origins. First, scanning through several candidate metal halide inorganic frameworks as well as their parental form halide perovskites, we find that the germanium triiodide (GeI3) column also assumes a semimetallic character by avoiding the Peierls distortion. Next, adopting the bundled nanowire GeI3-TMSGeI3-GeI3 junction configuration, we obtain a drastically high peak current density and ultrahigh NDR at room temperature. Furthermore, the robustness and controllability of NDR signals from GeI3-TMSGeI3-GeI3 devices under strain are revealed, establishing its potential for flexible electronics applications. It will be emphasized that, despite the performance metrics notably enhanced over those from the TMSPbI3 case, these device characteristics still arise from the identical quantum hybridization NDR mechanism.

Nanocrystal co-existed highly dense atomically disperse Pt@3D-hierarchical porous carbon electrocatalysts for tri-iodide and oxygen reduction reactions

The fabrication of highly dense atomically dispersed platinum (Pt) on a carbon matrix increases the catalytic sites and is one of the ways to utilize Pt to make inexpensive and highly efficient electrocatalysts. We have employed a three-dimensional hierarchical porous carbon (3D-HPC) substrate and nanocrystal co-existed highly dense Pt single atoms deposited by the incipient wetness impregnation method. The special structure of the 3D-HPC substrate favors the homogeneous dispersion of Pt all over the 3D-HPC, leading to nanocrystal co-existed highly dense atomically disperse Pt@3D-HPC. The as-prepared Pt@3D-HPC shows outstanding catalytic properties towards tri-iodide and oxygen reduction reactions (ORR). The Pt@3D-HPC electrode shows lower charge transfer resistance (Rct) at the electrode/electrolyte interface with narrow peak-to-peak separation (△Epp) and higher peak current density during the tri-iodide reduction reaction (IRR). The DSSC fabricated with a Pt@3D-HPC electrode shows improved performance compared to the reference Pt counter electrode (CE). Furthermore, CV and LSV demonstrate the better catalytic activity of Pt@3D-HPC towards ORR, with higher onset potential (Eonset), half-wave potential (E1/2), and current density (j) compared to the reference 20% Pt/C electrode. Furthermore, impressive mass activity was observed by the Pt@3D-HPC catalyst compared to 20% Pt/C and other recently reported single atom-based catalysts. The Pt@3D-HPC catalyst also shows improved stability towards IRR and ORR. This simple strategy to fabricate nanocrystal co-existed highly disperse Pt@3D-HPC catalysts with outstanding electrocatalytic performance and stability paves the way for its practical application and provides insights into a new approach to the design of electrocatalysts applicable to energy-related devices.

Facile in Situ Transformation of NiOOH into MOF-74(Ni)/NiO OH Heterogeneous Composite for Enchancing Electrocatalytic Methanol Oxidation.

A new MOF-74(Ni)/NiOOH heterogeneous composite was synthesized via NiOOH microsphere precursor. The electrocatalytic methanol oxidation reactions’ (MOR) performance was assessed. The as-prepared MOF-74(Ni)/NiOOH exhibited excellent activity with high peak current density (27.62 mA·cm−2) and high mass activity (243.8 mA·mg−1). The enhanced activity could be a result of the synergistic effect of the MOF-74(Ni)/NiOOH heterocomposite providing more exposed active sites, a beneficial diffusion path between the catalyst surface and electrolyte, and improved conductivity, favorable for improving MOR performance.

Fabrication of crystalline submicro-to-nano carbon wire for achieving high current density and ultrastable current

Crystalline carbon nanowire arrays were fabricated taking advantage of near-field electrospinning and stress decyanation. A novel fabrication method for carbon nanowires with radii ranging from ~2.15 µm down to ~25 nm was developed based on implementing nitrogen pretreatment on the silica surface and then aligning polymer nanofibers during near-field electrospinning at an ultralow voltage. Stress decyanation was implemented by subsequently pyrolyzing a polymer nanofiber array on the silica surface at 1000 °C for 1 h in an N2 atmosphere, thus obtaining a crystalline carbon nanowire array with a nanostructured surface. Various crystalline nanostructures were fabricated on the nanowire surface, and their electrochemical performance was evaluated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Crystalline carbon wires with diameters ranging from micrometers to submicrometers displayed carbon nanoelectrode-like behavior with their CV curve having a sigmoidal shape. A highly crystalline carbon nanowire array showed distinct behavior, having a monotonically increasing straight line as its CV curve and a semicircular EIS spectrum; these results demonstrated its ultrastable current, as determined by electron transfer. Furthermore, nanocrystalline-structured carbon wires with diameters of ~305 nm displayed at least a fourfold higher peak current density during CV (4000 mA/m2) than highly crystalline carbon nanowires with diameters of ~100 nm and porous microwires with diameters of ~4.3 µm.

Electroluminescence of atoms in a graphene nanogap.

Here, we report light emission from single atoms bridging a graphene nanogap that emit bright visible light based on fluorescence of ionized atoms. Oxygen atoms in the gap shows a peak emission wavelength of 569 nm with a full width at half maximum (FWHM) of 208 nm. The energy states produced by these ionized oxygen atoms bridging carbon atoms in the gap also produce a large negative differential resistance (NDR) in the transport across the gap with the highest peak-to-valley current ratio (PVR = 45) and highest peak current density (~90 kA/cm2) ever reported in a solid-state tunneling device. While tunneling transport has been previously observed in graphene nanogaps, the bridging of ionized oxygen observed here shows a low excess current, leading to the observed PVR. On the basis of the highly reproducible light emission and NDR from these structures, we demonstrate a 65,536-pixel light-emitting nanogap array.

Graphene Quantum Dots Supported Mo3S4 as a Promising Candidate for Pt-Free Counter Electrode in Dye-Sensitized Solar Cell and Supercapacitor Applications

We have synthesized with and without graphene quantum dots (GQDs) supported Molybdenum sulfide (Mo3S4/GQDs) by the hydrothermal route and examined the effect on electrochemical and dye sensitized solar cells (DSSCs) performance. The crystalline structure and composition are elucidated by X-ray diffraction and X-ray photoelectron spectroscopy, respectively. The synthesized samples show a spherical nature which is confirmed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). JV spectra reveal GQDs modified Mo3S4 counter electrodes deliver the highest short circuit current (J SC ) of 13.84 mA cm−2, open-circuit voltage (V OC ) of 0.72 V, and power conversion efficiency (PCE) of 5.67%, which is 13% higher compared to pristine counter electrodes. Low peak to peak separation (Epp) and higher peak current density (Jpc) and exchange current density (Jo) are responsible for this improvement. Besides, the samples have been employed as a working electrode and studied supercapacitor performance. Among them, Mo3S4/GQDs exhibited the highest specific capacitance of 234 F g−1 at 2 A g−1. The results mentioned above reveal GQDs supported Mo3S4 is not only a viable substitute for Pt-free counter electrodes but also provide a better outlook for energy storage devices.

High Band-to-Band Tunneling Current in InAs/GaSb Heterojunction Esaki Diodes by the Enhancement of Electric Fields Close to the Mesa Sidewalls

InAs/GaSb heterojunction Esaki diodes with a high peak current density of 9 MA/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> are demonstrated. Negative differential resistance (NDR) is achieved from 300 to 4 K, showing that band-to-band tunneling (BTBT) is the dominant transport mechanism. By increasing the doping concentrations, the peak current increases because of more carriers available for tunneling. NDR is also clearly observed for the devices with nondegenerate doping concentrations, which could be attributed to the induced quantum wells at the InAs/GaSb heterojunction. To calibrate the BTBT current, devices of different mesa areas were characterized. The peak current density increases as the device is scaled down. A model of tunneling enhancement close to the mesa sidewalls by the surface defects is proposed. TCAD simulations show that the electric fields close to the sidewalls are enhanced because of the induced surface defects by dry etching in InAs and GaSb. Careful processing steps to reduce those surface defects during etching steps are required to avoid an overestimation of the BTBT current.

3D nickel diselenide architecture on nitrogen-doped carbon as a highly efficient electrode for the electrooxidation of methanol and urea

The development of an electrocatalyst for the efficient catalysis of methanol or urea is essential for solving energy and environmental problems. This study successfully synthesizes nickel selenide and 3D nickel diselenide architectures on N-doped carbon using a NaCl-assisted method and selenization temperature regulation. The 3D architecture of the nickel diselenide with N-doped carbon obtained by selenization at 450 °C (NiSe2/NC-450) is a useful electrocatalyst for the methanol oxidation reaction (MOR) and urea oxidation reaction (UOR). This NiSe2/NC-450 electrode displays good catalytic activity for MOR (high peak current density of ~164.68 mA cm−2, low oxidation potential of ~1.33 V at 10 mA cm−2) and UOR (high peak current density of ~136.04 mA cm−2, low oxidation potential of ~1.32 V at 10 mA cm−2). The strong methanol and urea reaction performance of NiSe2/NC-450 is attributed to the expanded electrochemically active area after selenization and the enhanced conductivity after N-doped carbon. This study provides a new way to prepare and utilize inexpensive transition metal-based materials as efficient and stable anodic oxidation electrocatalysts.

Control of Texture and Morphology of Zinc Films through Pulsed Methods from Additive‐Free Electrolytes

AbstractWe investigate the electrodeposition of zinc on steel substrates using pulsed methods from additive‐free electrolytes in an industrially scalable parallel plate flow cell. We demonstrate that variables such as peak current and duty cycle can be used to independently control the morphology and preferential texture of the crystalline structure, which is, in turn, desirable for a variety of applications. Specifically, we have observed a transition of the preferential (002) facets at low peak current density (or low duty cycle) to (101) preferring facets at higher peak current density (or high duty cycle) as determined by the analysis of texture coefficients. Further analysis using scanning electron microscopy reveals a transition from the conventional hexagonal‐shaped particles of zinc to needle‐shaped structures, accompanied by a change in average crystallite size from 33 to 19 nanometers, determined from X‐ray diffraction studies. The variation in morphology is also correlated to crystallographic textures through the analysis of texture coefficients and an understanding of crystallization mechanisms occurring during deposition. Collectively, these results demonstrate that the morphology and crystalline orientation of zinc can be easily manipulated through tuning of the pulse parameters without the use of complex and expensive additives that have been traditionally used to achieve similar effects.

(Invited) Advanced Catalysts for Efficient Electrochemical Ammonia Oxidation

Ammonia (NH3) has proved to be an effective alternative to hydrogen in low-temperature fuel cells via its direct ammonia oxidation reaction (AOR)(1). However, the kinetically sluggish AOR has prohibitively hindered the attractive direct ammonia fuel cell (DAFC) applications. Here, we report an efficient AOR catalyst, in which ternary PtIrM (M: Ni or Zn) alloy nanoparticles well dispersed on a binary composite support consisting of porous silicon dioxide (SiO2) and carboxyl-functionalized carbon nanotube (PtIrNi/SiO2-CNT-COOH) through a sonochemical-assisted synthesis method (2). The PtIrNi alloy nanoparticles, with the aid of abundant OHad provided by porous SiO2 and the improved electrical conductivity by CNTs, exhibit remarkable catalytic activity for the AOR in alkaline media. It is evidenced by a lower onset potential (∼0.40 V vs reversible hydrogen electrode (RHE)) at room temperature than that of commercial PtIr/C (ca. 0.43 V vs RHE). Increasing NH3 concentrations and operation temperatures can significantly enhance AOR activity of this PtIrNi nanoparticle catalyst. Specifically, the catalyst at the temperature of 80 °C exhibits a much lower onset potential (∼0.32 V vs RHE) and a higher peak current density, indicating that DAFCs operated at a higher temperature are favorable for increased performance.References(1) Adli, N. M.; Zhang, H.; Mukherjee, S.; Wu, G., Review—Ammonia Oxidation Electrocatalysis for Hydrogen Generation and Fuel Cells. Journal of The Electrochemical Society 2018, 165 (15), J3130-J3147.(2) Li, Y.; Li, X.; Pillai, H. S.; Lattimer, J.; Mohd Adli, N.; Karakalos, S.; Chen, M.; Guo, L.; Xu, H.; Yang, J.; Su, D.; Xin, H.; Wu, G., Ternary PtIrNi Catalysts for Efficient Electrochemical Ammonia Oxidation. ACS Catalysis 2020, 10 (7), 3945-3957.

Common Strategy: Mounting the Rod-like Ni-Based MOF on Hydrangea-Shaped Nickel Hydroxide for Superior Electrocatalytic Methanol Oxidation Reaction.

Developing efficient metal-organic framework (MOF)-based electrocatalysts with improvable activity and persistence toward the methanol oxidation reaction (MOR) is attracting great research attention but still remains an enormous challenge. Herein, a facile strategy, hydrangea-shaped nickel hydroxide template-directed synthesis of the hierarchically structured Ni-MOF on the Ni(OH)2 heterocomposite (denoted as Ni-Ni) for efficient MOR, is developed. The unique hierarchical structure and synergistic effect of the heterocomposite afford more exposed active sites, a facile ion diffusion path, and improved conductivity, favorable for improving MOR catalytic performance. Remarkably, the optimized Ni-Ni-2 material delivers an excellent activity with a high peak current density (24.6 mA cm-2). Furthermore, to prove the universality of this strategy, NixCu1-x(OH)2 isometallic hydroxide was used as the precursor, and a series of MOF-74/CuxNi1-x(OH)2 (denoted as Ni-NiCu) heterogeneous materials have been prepared and could be used as an effective electrocatalyst to catalyze MOR. The results indicate that this strategy can be used in the synthesis of other new composite materials with specific hierarchical structures for a more efficient electrocatalytic system.

Modulation of Negative Differential Resistance in Black Phosphorus Transistors.

Negative differential resistance (NDR), which describes the current decrease as the applied bias increases, holds great potential for varieties of electronic applications including radio-frequency oscillators, multipliers, and multivalue logics. Here, the modulation of a unique NDR effect in ambipolar black phosphorus (BP) transistors is reported, which is activated by specific electrical field dependence of lateral carrier distribution and is distinct from conventional NDR devices that rely on quantum tunneling. The NDR device exhibits a high peak current density (34 µA µm-1 ) and a high operating temperature. More importantly, due to the strong coupling between the channel and the gate electrode, both the NDR peak current and peak/valley voltages can be effectively modulated by the electrostatic gate. Furthermore, it is demonstrated that light can serve as an additional terminal for NDR modulation. The findings could provide an important insight into the transport behavior of BP transistors and contribute to the design of ambipolar-semiconductor-based electrical circuits.