Substrate materials for high performance self-supporting oxygen catalytic electrodes
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摘要: 在“碳達峰”和“碳中和”的時代背景下,電解水、金屬空氣電池、燃料電池等清潔能源技術由于具有能量效率高、安全性好、結構簡單和清潔環保等優點受到廣泛關注。然而,發生在氧催化電極上的關鍵反應——氧還原反應(ORR)和氧析出反應(OER)具有緩慢的動力學,很大程度上阻礙了其商業化應用。傳統氧催化電極存在合成過程繁瑣、可控性低、均一性差、成本高和載體催化劑易團聚等問題,限制了其催化性能。自支撐氧催化電極的高催化活性位點、高穩定性等優勢可以完美解決傳統電極面臨的問題。本文介紹了自支撐氧催化電極基底材料的研究進展以及合成方法,并討論了影響自支撐氧催化電極ORR/OER催化性能的因素,最后對自支撐氧催化電極未來的研發方向和發展趨勢提出展望。Abstract: Under the background of peak carbon dioxide emissions and achieving carbon neutrality, clean energy technologies such as water electrolysis, metal–air batteries, and fuel cells have attracted extensive attention due to the advantages of high efficiency, good safety, a simple structure, low cost, and eco-friendliness. However, the key reactions on oxygen catalytic electrodes, the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), are kinetically sluggish, which considerably hinders their commercial applications. The traditional oxygen catalytic electrodes with the use of binders have the disadvantages of a cumbersome synthesis process, low controllability, poor uniformity, high cost, and easy carrier catalyst agglomeration, which limit their catalytic performance. Recently, self-supported oxygen catalytic electrodes have attracted extensive attention due to their advantages of high catalytic active sites and a stabilized spatial framework, which can solve the problems faced by traditional oxygen catalytic electrodes and further improve the catalytic performance of the electrode. As the catalyst material carrier, the substrate materials play an important role in the catalytic performance of self-supporting oxygen electrodes. The high interaction forces between the substrate and the catalyst material lead to a single-direction growth orientation and uniform dispersion. Reportedly, the substrate materials for self-supporting oxygen catalytic electrodes have not been fully discussed in comprehensive reviews. Therefore, timely updates in this potential field must be provided. This paper summarizes the research progress and synthesis methods of commonly self-supporting oxygen catalytic electrodes based on different substrate materials, including two- and three-dimensional metal materials and carbon materials. In addition, this paper introduces the outstanding ORR/OER catalytic properties of common self-supporting oxygen catalytic electrodes, which are not only due to the intrinsic catalytic activity of the supported catalytic active materials but also related to the high specific surface area and high electron transfer rate caused by the structure of the self-supported electrode substrate. Finally, the future research and the development trend of self-supporting oxygen catalytic electrodes are addressed from the four aspects of density general function theory, improving electrode energy density, constructing an efficient gas–liquid–solid three-phase interface of an electrode, and establishing a standard evaluation protocol of self-supported oxygen catalytic electrodes. This review should provide new research insights for developing renewable energy storage and conversion systems.
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圖 1 Co–Nx/C納米棒陣列[24]. (a)合成示意圖; (b) SEM圖; (c) ORR/OER極化曲線
Figure 1. Co–Nx/C nanorod array: (a) diagrammatic scheme; (b) SEM image; (c) ORR/OER polarization curves
圖 2 Ni/Co氧化物催化劑及性能[35]. (a) (Ni,Co)3O4@Ni-foam24的SEM圖; (b) Pt/C+IrO2和(Ni,Co)3O4@Ni-foam電極的OER曲線; (c) Pt/C+IrO2和(Ni,Co)3O4@Ni-foam電極的ORR曲線; (d~f) CoP–MNA電極的SEM圖
Figure 2. Ni/Co catalyst and performance: (a) SEM image of (Ni,Co)3O4@Ni-foam24; (b) OER curves of Pt/C+IrO2 and (Ni,Co)3O4@Ni-foam electrodes; (c) ORR curves of Pt/C+IrO2 and (Ni,Co)3O4@Ni-foam electrodes; (d–f) SEM image of CoP–MNA electrode
圖 4 Cu-Foam@CuCoNC-500自支撐電極及性能[48]. (a)合成示意圖; (b) SEM圖; (c) 鋅空氣電池的不同電流密度下的放電電壓圖
Figure 4. Cu-Foam@CuCoNC-500 self-supporting electrode and performance: (a) diagrammatic scheme; (b) SEM image; (c) the discharge voltage of zinc air battery under different current densities
圖 5 Co/CNF電極的微觀形貌[51]. (a)光學照片; (b~d) SEM圖
Figure 5. Microstructure of Co/CNF electrode: (a) optical photo; (b–d) SEM image
圖 7 Fe0.33Co0.67OOH PNSAs/CFC自支撐電極[56]. (a) 合成示意圖; (b) 10 mA·cm–2下的耐久性測試; (c~d) SEM圖; (e) α-Co(OH)2到Fe0.33Co0.67OOH的結構轉變示意圖
Figure 7. Fe0.33Co0.67OOH PNSAs/CFC self-supporting electrode: (a) preparation of diagram; (b) durability test at 10 mA·cm–2; (c–d) SEM images; (e) schematic diagram of structural transformation from α-Co(OH)2 to Fe0.33Co0.67OOH
表 1 泡沫鎳自支撐電極的電化學性能
Table 1. Electrochemical performance of nickel foam self-supported electrode
Electrode Electrolyte ORR OER ?E/V Full battery test Ref. E1/2/V j/(mA·cm–2) Tafel slope/
(mV·dec–1)η10 /mV Tafel slope/
(mV·dec–1)Battery Power density/
(mW·cm–2)(Ni,Co)3O4@Ni-foam electrode 1 mol·L–1 KOH 0.84 — — 180 — 0.57 Zn–air batteries 74 [35] NiFeMoS/NF–P 1 mol·L–1 KOH — 150 — 280 69 — — — [36] Ni3S2/MoSx na-nosheets/NF 1 mol·L–1 KOH — 150 — 305 67.5 — — — [37] (Ni0.33Fe0.67)2P electrode 1 mol·L–1 KOH — 50 — 230 55.9 — — — [42] CoFePO 1 mol·L–1 KOH — — — 274.5 51.7 — — — [34] CoP–MNA 1 mol·L–1 KOH — — — 290 65 — — — [19] CuCoOx/FeOOH 1 mol·L–1 KOH 0.78 5.3 — 270 63 0.72 Zn–air batteries 158 [38] Co3O4/NCNTs/3D graphene 0.1 mol·L–1 NaOH 0.80 — 66.18 — — — Al–air coin batteries 4.88 [39] NF@Co3–xNixO4 1 mol·L–1 KOH 0.91(Eonset) — — 310 — — Zn–air batteries — [40] MnO2–NiFe electrode 1 mol·L–1 KOH 1.01(Eonset) 4.26 126.1 226 251.3 0.65 Zn–air batteries 93.95 [41] MnOx–S 0.1 mol·L–1 KOH 0.95(Eonset) — 68 — 80 0.78 Zn–air batteries 69 [43] Mn–Ni3S2/NF 0.1 mol·L–1 KOH 0.347 — 107.5 — 69.3 — Zn–air batteries 75.8 [44] 表 2 鋅空氣電池的雙效碳布基自支撐電極電化學性能
Table 2. Electrochemical performance of the double-effect carbon substrate self-supported electrode for zinc–air battery
Electrode ORR OER ?E / V Ref. J /(mA·cm–2) E1/2 / V η j=10 / mV N–GQDs/NiCo2S4/CC 4.71 0.86 340 j=30 0.71 [57] Co3O4–x HoNPs@HPNCS-60 5.82 0.83 313 0.74 [58](2019a) NC–Co3O4/CC-600 — — 210 0.87 [59] SS–Co–SAC NSAs 59.1 0.81 348 0.77 [60] Co4N/CNW/CC 16.5 0.80 310 0.74 [61] FeNO–CNT–CNFF-800 — 0.87 — 0.79 [62] Co–FeCo/N–G 2.28 0.82 258 — [63] NPC/Fe–N–C 5.2 0.87 — — [64] www.77susu.com -
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