Composite Functional Materials

Figure/Table detail

Recent advances and applications of on-chip micro-/nanodevices for energy conversion and storage

Haiyan Xiang, Jan E. Lopez, Travis Hu, Jiayuan Cheng, Jizhou Jiang, Huimin Li, Tang Liu, Song Liu

Composite Functional Materials, 2025, 1(1): 20250102. DOI: 10.63823/20250102

Strategies	Types	Materials	Performances	Electrolyte	Ref.
Identification of active sites	Basal and edge	2H and 1T'-MoS₂ monolayers	(2H)basalη₁₀=−425±27 mV Edge η₁₀=−201±42 mV (1T')basalη₁₀=−356±41 mV Edge η₁₀= −77 ± 24 mV	0.5 M H₂SO₄	^[64]
		2H-MoS₂ basal plane with the vacancy	η₁₀ ≤ −150 mV	0.5 M H₂SO₄	^[80]
		helical WS₂	η=−560 mV (vs Ag/AgCl) (20 nA μm⁻²)	0.5 M H₂SO₄	^[104]
		WTe₂	η(100)= −320 mV	0.5 M H₂SO₄	^[105]
	phase and layer	1T'-MoS₂ 2H/1T′-MoS₂	η= −65 mV η= 200 mV	0.5 M H₂SO₄	^[82]
		Heterophase boundaries between the 2H and 1T’ phases in MoTe₂	η= -210 mV	0.5 M H₂SO₄	^[107]
		PtSe₂	Monolayer η=60 mV Thick η=550 mV	0.5 M H₂SO₄	^[106]
	Catalytic window	2H-MoS₂	η=−290 mV	0.5 M H₂SO₄	^[108]
Monitoring the performance at a single material.	GBs and S vacancies	MoS₂ nanograin film	η₁₀=−25 mV	0.5 M H₂SO₄	^[112]
	Doping	P-MoS₂	η₁₀=−297 mV	0.5 M H₂SO₄	^[113]
	Doping	V-MoS₂	η₁₀=−185 mV	0.5 M H₂SO₄	^[116]
	Design single atom	Mo-MoS₂	η₁₀=−107 mV	0.5 M H₂SO₄	^[145]
	Design single atom	Amorphous PtSe_x	η=−100 mV	0.5 M H₂SO₄	^[115]
	Construct Heterostructure	MoS₂/graphene	η₁₀=−110 mV	0.5 M H₂SO₄	^[105]
	Construct Heterostructure	Methylene blue (MB)/MoS₂ interfaces	η₁₀=−206 mV	0.5 mM MB	^[118]
	Electric Field Modulation	MoOx/MoS₂ core-shell nanowires	η=−200 mV	0.5 M H₂SO₄	^[119]
		MoS₂ at the gate voltage of 5 V	η₁₀=−38 mV	0.5 M H₂SO₄	^[120]
		VSe₂	η₁₀=−126 mV	0.5 M H₂SO₄	^[81]
		WSe₂ with back-gate voltage 20 V	η₁₀=−280 mV	0.5 M H₂SO₄	^[124]
		(CoPc)/MoS₂with back-gate voltage 2V	η₁₀=−238 mV	0.5 M H₂SO₄	^[130]
		Pt SAs on n-type MoS₂ with Vg +40 V	η₁₀=−20 mV	0.5 M H₂SO₄	^[130]
	Thermal Modulation	inert MoS₂ ML basal plane at 60 °C	η₁₀=−90mV	0.5 M H₂SO₄	^[131]

Table 1 Summary of on-chip HER electrocatalytic devices.

Other figure/table from this article

Figure. 1 Timeline for the on-chip microcell in electrocatalysis.^[77] Copyright (2010) American Chemical Society; ^[78] Copyright (2014) Nature Publishing Group; ^{[68, 79]} Copyright (2015) American Chemical Society and Nature Publishing Group; ^{[66, 80]} Copyright (2016) American Chemical Society and Nature Publishing Group; ^{[67, 81]} Copyright (2017) American Chemical Society; ^[82] Copyright (2018) Nature Publishing Group; ^[69] Copyright (2019) Nature Publishing Group; ^[83] Copyright (2020) Nature Publishing Group; ^{[84, 85]} Copyright (2022) Wiley-VCH Verlag GmbH & Co and American Chemical Society; ^[86] Copyright (2024) Nature Publishing Group.
Figure. 2 (a) Annual number of publications by using keyword of “on-chip electrocatalysis” from Web of Science on January 7, 2025. (b) The hot spot in the total circulation.
Figure 3. An analysis of practical configuration, lab testing equipment and on-chip micro-device. ^[96] Copyright 2019, Elsevier Ltd. All rights reserved.
Figure 4. (a) Schematic of the on-chip setup. Optical image of a MoS₂showing the (b) basal and (c) edge planes. (d) LSV and (e) Tafel plots of the MoS₂with basal plane and edge, the electrolyte was argon-purged in 0.5 M H₂SO₄ and scan rate was set at 10 mV s⁻¹. (f) LSV and (g) Tafel curves of monolayer 1T′-MoS₂ basal plane, and edge in HER.^[64] Copyright 2017, Wiley-VCH Verlag GmbH & Co. (h1) Photograph of the electrochemical microcell. (h2) Schematic of the on-chip electrocatalytic. Optical microscope images of single-layer MoS₂ with (h3) the basal and (h4) edge exposed.^[80] Copyright 2016, Nature Publishing Group. (i1, i2) AFM of spiral WS₂ domains and (i3) corresponding height of monolayer WS₂. (i4) Schematic of the spiral domain growth modes. (i5) Schematic of the atomic arrangement in spiral WS₂.^[104] Copyright 2019, American Chemical Society. (j1) LSV of MoS₂ and WTe₂ with different exposed area, the overpotential of (100), (010) edge and basal plane is 320 ± 10 mV, 350 ± 10 mV and 390 ± 20 mV respectively at 10 mA cm⁻². (j2) Summary of the overpotentials for WTe₂ with different exposed sites. (j3) LSV of WTe₂ with basal plane. (j4) LSV of MoS₂ with a graphene contact, as well as from the MoS₂/graphene heterostructure.^[105] Copyright 2018, Wiley-VCH Verlag GmbH & Co.
Figure 5. The diagram of fabrication process. (b) The LSV for EM-1, EM-2, and EM-3, with an inset image EM-1, the overpotential of EM-1 and EM-2 is 165 mV and 200 mV, respectively. Scale bar, 20 μm (c) Tafel plots corresponding the (b).^[82] Copyright 2018, Nature Publishing Group. (d) Optical images of CVT-grown PtSe₂ flakes ranging from 1 to 20 layers, insets show the corresponding AFM images. (the same height scale for AFM images, the scale bar of first is 1 μm, others is 0.5 μm) (e) LSV and Tafel slops for the HER. (f) ΔG_Hdiagram for HER of different layer PtSe₂.^[106] Copyright 2019, Wiley-VCH Verlag GmbH & Co.
Figure 6. (a1) The HAADF STEM image of the GBs between three MoS₂ grains, the inset on the left shows the Fourier transform. (a2) The composite color-coded inverse fast Fourier transform (IFFT) image. (a3) illustrates the Geometrical Phase Analysis (GPA) routine.^[112] (b1) Schematic of HER process on P-MoS₂ nanosheets. (b2) and (b3) show the LSV and Tafel plots for the MoS₂ and P-MoS₂, The edge sites show an onset potential (η₁₀) of 297 mV and a Tafel slope of 97 mV dec⁻¹ for HER, exceeding those of the basal plane with 328 mV and 108 mV dec⁻¹. (b4) Optical images of edge and basal plane on a P-MoS₂. (b5) and (b6) display the electrochemical and electronic signals of a MoS₂ and P-MoS₂ during the HER. (b7) Illustrates the electronic structure of P-MoS₂, aligning the Fermi levels.^[113] Copyright 2017, American Chemical Society. (c1) Schematic of the active sites of MoS₂. (c2) Schematic of Mo ML-MoS₂. (c3) Details the synthesis of metal SAs on a ML-MoS₂. HAADF-STEM images in panels (c4) and (c5) depict Mo SAs on ML-MoS₂ and tungsten SAs on monolayer WS₂ samples, respectively. (c6) statistical results on the density of Mo and W SAs on 2D monolayers.^[114] Copyright 2020, American Chemical Society. (d) Schematic of the amorphous PtSe_x surface, perfect PtSe₂ and defective PtSe_x.^[115] Copyright 2022, Nature Publishing Group.
Figure 7. (a) Schematic of the gate-modulation electrochemical device. (b) Optical images of 2H-MoS₂ with Au pads. (c) LSV of gate-dependent HER measurements, the green and red curves show the improvement in electrocatalytic activity after applying a positive gate voltage of 10 and 20 V, respectively.^[119] (d) Energy band diagrams of the MoS₂ device at diﬀerent gate bias.^[120] Copyright 2017, Wiley-VCH Verlag GmbH & Co. (e) Schematic of the HER device under back gate voltages. (f) Statistic-based influence of the back gate on the onset overpotential and Tafel slope.^[81] Copyright 2017, American Chemical Society. (g) Schematic of a back-gated electrochemical cell. (h) Energy band diagrams of the MoS₂at various back-gate biases.^[67] Copyright 2017, American Chemical Society.
Figure 8. (a) Schematic of the microcell-based in situ electronic/electrochemical measurement. (b) Optical image of the microcell. (c) Typical electrochemical (y axis in black) and electronic (y axis in red) signals of single-layer WS₂ during the HER at different bias potentials. Self-gating phenomenon of (d) n-type MoS₂, (e) p-type WSe_1.8Te_0.2, and (f) bipolar WSe₂, typically, n-type MoS₂ is turned on at a negative electrochemical potential and only delivers the HER, p-type WSe_1.8Te_0.2 is turned on at a positive electrochemical potential and only delivers the OER, bipolar WSe₂ is turned on at both negative and positive electrochemical.^[69] Copyright 2019, Nature Publishing Group. (g) Schematic of the Pt NW device. (h) SEM image of the device cell. (i) Schematic of CV and ETS for in situ monitoring of the electrochemical interfaces. (j) The I_G-V_G and normalized G_SD-V_G characteristics of a typical Pt NW device, I_G-V_G resembles the typical CV characteristic of a polycrystalline Pt surface, containing redox regions of HER, H adsorption/desorption region (Hupd), double layer (DL) region, surface oxide formation/reduction region (Oupd) and OER. (k) The differentiated ETS curve illustrates spectral peak characteristics. (l) Schematic of various Pt surface conditions along with the sweeping electrochemical potentials (left black axis) and the corresponding changes in conductivity.^[68]
Figure 9. (a) Schematic of an STM-based time-dependent tip-enhanced Raman spectroscopy (TERS).^[140] Copyright 2016, Nature Publishing Group. (b) Schematic illustration of the in situ XAS liquid cell.^[142] Copyright 2018, Nature Publishing Group. (c) Schematic of the experimental setup for operando X-ray reflectivity of SrTiO₃.^[141] Copyright 2016, American Chemical Society. (d) Schematic illustration of the in situ XPS experimental set-up.^[143] Copyright 2018, Wiley-VCH Verlag GmbH & Co. Designed flow cell for performing in situ Raman measurements to distinguish between (e) an abrupt interface and (f) a gradient interface. (g) The cell design with both top and side views of the cathode area.^[144] Copyright 2020, American Chemical Society.
Figure 10. (a) Schematic of the formation process of the Cr-WSe₂/graphene heterojunction. (b) Schematic of the on-chip electrocatalytic device.^[85] Copyright 2022, American Chemical Society. (c) In situ I-V measurements of individual Co₃O₄, P₀-Co₃O₄ and P-Co₃O₄ thin-films. Inset: The schematic of in situ I-V measurements. The applied potentials in WE1 and WE2 (called V1 and V2) increase synchronously vs. RHE, from 1 to 1.8 V, and keep the constant tiny potential difference ΔV (ΔV=1 mV).^[159] Copyright 2021, Elsevier Ltd. All rights reserved. (d) On-chip electrochemical measurement setup for the ORR. (e) Schematic illustration of the setup. (f) Schematic diagram of the static and microfluidic PDMS cells.^[84] Copyright 2022, Wiley-VCH Verlag GmbH & Co.
Figure 11. (a) The relationship between the thicknesses of Pd and Pd₄Ag nanowire films and their phase transition responses (ΔR_MHx) is illustrated on the ETS. (b) Schematic of electron scattering in metals with surface adsorbates and hydrides. A schematic of the different Pd-H states in (c) KHCO₃ and (d) K₂HPO₄/KH₂PO₄ and the corresponding CO₂RR processes at the interfaces. (e) Summary of phase transition potentials of Pd and Pd₄Ag under CO₂RR conditions in KHCO₃ and K₂HPO₄/KH₂PO₄ obtained at 10 mV/s.^[172] (g1, g2) Schematic of the nanoelectronic measurement setup. (g3) Optical microscope (OM) image of MR-1 in dark-field mode. (g4) An ex situ SEM image of MR-1. (g5) Schematic of biofilm measurements. (g6) Schematic of the electrochemistry model at the interface of Shewanella oneidensis MR-1.^[173] Copyright 2016, American Chemical Society.
Figure 12. (a) Schematics of fabrication process of the single nanowire photovoltaic device. (b, c, d) SEM images corresponding to schematics in a.^[91] Copyright 2007, Nature Publishing Group. (e, f) The schematics and dark ﬁeld optical microscopic image of the nanowire electrode. (g) The second conﬁguration, in which the nanowire is covered by a passivation layer with only one exposed end. (h) The SEM image of the device with the second conﬁguration.^[79] Copyright 2015, American Chemical Society. (i) Schematic of MoS₂-Li microbattery.^[180] Copyright 2015, Wiley-VCH Verlag GmbH & Co. (j) Schematic of the device for lithium ion diffusion in bilayer graphene. The inset shows the Raman scattering response of bilayer graphene.^[181] Copyright 2017, Nature Publishing Group.
Figure 13. (a) Illustration of atomic defects observed in single-layer V-MoS₂. (b) Statistical analysis of the concentration of these atomic defects.^[116] Copyright 2022, Wiley-VCH Verlag GmbH & Co. (c) Structural diagram of P-Co₃O₄. (d) Total electronic density of states for Co₃O₄ and P-Co₃O₄. (e) Calculated PDOS of Co₃O₄ and P-Co₃O₄. (f) Calculated free energy diagram of the OER on Co₃O₄ and P- Co₃O₄.^[159] Copyright 2021, Elsevier Ltd. All rights reserved. (g) The schematic of the S vacancy site created on the modeled MoS₂ surface. (h) The computed band structures of the MoS₂ surface with 5.5% S vacancies at various induced charge levels. (i) The charge density difference of a monolayer of MoS₂ with 5.5% S vacancies.^[192] Copyright 2019, American Chemical Society.
Figure 14. (a) Fabrication and structural characterization of SST-MPCs.^[205] Copyright 2018, Nature Publishing Group. (b) Schematic of the fabrication process of SST-MPCs.^[206] Copyright 2015, Wiley-VCH Verlag GmbH & Co. (c) Schematic of the printable fabrication procedure.^[207] Copyright 2017, Wiley-VCH Verlag GmbH & Co.
Figure 15. Prospects for on-chip microcells. The challenges in this emergent field, such as limited catalyst size. The applications of the on-chip microcells, e.g., the expansion, other application and advanced characterization are expected.