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  本文選題：電催化劑 + 析氧反應(yīng)�。� 參考：《西華師范大學(xué)》2017年碩士論文

【摘要】：對能源需求的增加以及化石燃料的枯竭加快了低碳、可再生、清潔能源的尋找。氫氣,由于其出色的能量密度和高效的轉(zhuǎn)換率被認(rèn)為是最理想的選擇。在工業(yè)上氫氣通常主要是由煤、石油和天然氣制得,但是隨之產(chǎn)生的副產(chǎn)品:一氧化碳和二氧化碳,其中二氧化碳將會造成全球變暖。電解水是產(chǎn)生高效、清潔的氫能源的有效化學(xué)途徑。貴金屬化合物顯示出最高的催化性能(IrO2/RuO2用于OER,Pt用于HER),但他們材料本身的高成本和稀缺性限制了其廣泛的應(yīng)用。雙功能催化劑的使用可以簡化制備過程從而降低成本。因此,尋找對OER和HER都有效的雙功能納米催化劑變得非常重要。本論文主要研究了基于鈷元素的納米材料的制備及在全電解水方面的應(yīng)用。主要包括以下內(nèi)容:1.通過一步法合成了鈦網(wǎng)上自支撐的無定形硒化鈷納米粒子(a-CoSe/Ti)。實(shí)驗(yàn)結(jié)果表明,所制備的硒化鈷納米粒子均勻分布在鈦網(wǎng)上,且厚度達(dá)到了10微米。在堿性條件下,該材料表現(xiàn)出較高的析氧和析氫催化活性并展現(xiàn)出很強(qiáng)的穩(wěn)定性。在電流密度達(dá)到10 m A cm-2的時候,對于析氧反應(yīng)硒化鈷納米粒子電極僅需292mV的過電位,析氫反應(yīng)僅需121 mV。同時用a-CoSe/Ti在堿性條件下作為雙電極體系電解水,電流密度達(dá)到10 mA cm-2的時候需要電壓1.65 V。這項(xiàng)工作對降低全電解水的應(yīng)用成本提供了新思路。2.我們第一次報導(dǎo)了在鈦片上通過電沉積一步法制備鈷摻雜的二硒化鎳納米粒子(Co0.13Ni0.87Se2/Ti)并探究其在堿性電解液中的催化性能。Co0.13Ni0.87Se2/Ti是一個高效、低成本且很穩(wěn)定的析氧和析氫三維電極。在1.0 M KOH中,Co0.13Ni0.87Se2/Ti在析氫反應(yīng)中需要64 m V過電勢達(dá)到電流密度10 mA cm-2,析氧反應(yīng)中也僅僅只需要320 mV過電勢達(dá)到電流密度100 mA cm-2。用Co0.13Ni0.87Se2/Ti作為陽極和陰極的兩電極堿性水電解,達(dá)到電流密度10 mA cm-2僅需要電壓1.62 V。3.通過密度泛函理論得知鋅元素?fù)诫s磷化鈷后其催化性能有很大提升。我們首次報導(dǎo)了通過兩步法在鈦網(wǎng)基底上合成了鋅摻雜的磷化鈷納米片(Zn0.08Co0.92P/TM)。把該材料用作酸性和堿性中的三維產(chǎn)氫催化劑時,Zn0.08Co0.92P/TM在酸性和堿性中表現(xiàn)出高效持久的析氫活性。在堿性兩電極體系中,為進(jìn)一步降低反應(yīng)所需的過電勢,我們向電解液中添加了一定濃度的尿素,實(shí)驗(yàn)結(jié)果表明在1.0 M KOH與0.5 M尿素的混合液中兩電極電解達(dá)到10 mA cm-2的電流密度僅需電壓1.38 V,比堿性兩電極電解水減少了0.26 V。
[Abstract]:Increased demand for energy and depletion of fossil fuels have accelerated the search for low-carbon, renewable, and clean energy. Hydrogen, due to its excellent energy density and high conversion rate, is considered to be the ideal choice. In industry hydrogen is usually made mainly from coal, oil and natural gas, but the byproducts are carbon monoxide and carbon dioxide, which will cause global warming. Electrolytic water is an effective chemical pathway for producing efficient, clean hydrogen energy. The noble metal compounds show the highest catalytic performance. IRO _ 2 / RuO _ 2 is used in the peroxidase, but their high cost and scarcity limit their wide application. The use of bifunctional catalysts can simplify the preparation process and thus reduce the cost. Therefore, it is very important to find two functional nano catalysts that are effective for both OER and HER. In this paper, the preparation and application of cobalt-based nanomaterials in electrolytic water were studied. Mainly include the following content: 1. The amorphous cobalt selenide nanocrystalline a-CoSe-TiN was synthesized by one-step method. The experimental results show that the prepared cobalt selenide nanoparticles are uniformly distributed on the titanium network and the thickness is up to 10 microns. Under alkaline conditions, the material exhibited high catalytic activity of oxygen evolution and hydrogen evolution and showed strong stability. When the current density is up to 10 Ma cm-2, only 292mV overpotential is required for oxygen evolution reaction of cobalt selenide nanoparticles electrode and 121mV for hydrogen evolution reaction. At the same time, when a-CoSe/Ti is used as electrolytic water with two electrodes in alkaline condition, the voltage is 1.65 V when the current density reaches 10 Ma cm-2. This work provides a new way to reduce the application cost of the whole electrolytic water. We report for the first time the preparation of cobalt doped nickel diselenide nanoparticles Co0.13Ni0.87Se2 / Ti on titanium wafer by one step electrodeposition method and investigate its catalytic performance in alkaline electrolyte. Co0.13Ni0.87Se2 / Ti is a highly efficient, low-cost and stable three-dimensional electrode for oxygen evolution and hydrogen evolution. Co0.13Ni0.87Se2 / Ti needs 64 MV overpotential to reach current density 10 Ma cm-2 in 1.0 M KOH, and only 320 MV overpotential to 100mA cm-2 in oxygen evolution reaction. Using Co0.13Ni0.87Se2/Ti as anode and cathode for alkaline water electrolysis of two electrodes, only 1.62 V. 3 voltage is required to achieve current density of 10 Ma cm-2. Through density functional theory, it was found that the catalytic activity of zinc doped cobalt phosphide was greatly improved. We report for the first time that zinc doped cobalt phosphide nanocrystals Zn0.08Co0.92P / TMN have been synthesized on titanium mesh substrates by two-step method. The Zn0.08Co0.92P / TM exhibits high and persistent hydrogen evolution activity in acid and alkalinity when it is used as a three-dimensional catalyst for hydrogen production in acidic and alkaline systems. In the alkaline two-electrode system, in order to further reduce the overpotential required for the reaction, we added a certain concentration of urea to the electrolyte. The experimental results show that the current density of 10 Ma cm-2 in the mixture solution of 1.0 M KOH and 0.5 M urea only requires a voltage of 1.38 V, which is 0.26 V less than that of alkaline two-electrode electrolytic water.
【學(xué)位授予單位】：西華師范大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：O643.36;TQ116.2

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本文編號：1777079