在太阳光电解中通过"Co-Pi"催化剂修饰的W:BiVO4几乎完全抑制了表面重组
Diane K Zhong1, Sujung Choi, Daniel R Gamelin
1Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, United States.
Journal of the American Chemical Society
|September 28, 2011
概括
将-- (Co-Pi) 电催化剂添加到 tungsten-doped bismuth vanadate (W:BiVO(4)) 光电极,可显著改善太阳能水的氧化. 这种表面修改提高了效率,并减少了光电化学 (PEC) 水分过程中的能量损耗.
科学领域:
- 材料科学 材料科学 材料科学
- 电化学 电化学 电化学
- 可再生能源可再生能源是可再生能源.
背景情况:
- 太阳能分水是可再生生产的关键技术.
- 配的慕瓦纳酸盐 (W:BiVO(4) 是一个有前途的光电极材料.
- 高效的氧化水电催化剂对于提高太阳能水分裂性能至关重要.
研究的目的:
- 为了研究地球上丰富的-- (Co-Pi) 电催化剂对太阳能水氧化的W:BiVO(4) 光电极的影响.
- 通过使用光电化学 (PEC) 技术,评估使用Co-Pi修改的W:BiVO(4) 光电极的性能提升.
- 评估Co-Pi修改策略在低成本太阳能水分应用中的潜力.
主要方法:
- 制造W:BiVO(4) 的光电极.
- 使用Co-Pi电催化剂对W:BiVO(4) 的表面修改.
- 在pH8下进行光电化学 (PEC) 测量,包括使用H(2) O(2) 作为替代基质的实验.
- 结果与Co-Pi/α-Fe(2) O(3) 光电极的比较.
主要成果:
- 在pH 8.下,Co-Pi的修饰诱导了持续的PEC水氧化开始潜力的显著阴极转移 (∼440 mV).
- 将Co-Pi与W:BiVO(4) 光电极连接起来,有效地抑制了表面电子孔重组损失.
- 通过Co-Pi/W:BiVO(4) 系统实现了≤310mV的低绝对发作潜力与RHE相比.
结论:
- Co-Pi/W:BiVO(4) 光电极显示了非常高效的太阳能氧化水.
- 观察到的改进对于开发低成本的PEC合电池来实现整体太阳能水分是有希望的.
- 这种表面修改策略适用于其他候选光电极材料.
相关概念视频
Thermal and Photochemical Electrocyclic Reactions: Overview
Electrocyclic reactions are reversible reactions. They involve an intramolecular cyclization or ring-opening of a conjugated polyene. Shown below are two examples of electrocyclic reactions. In the first reaction, the formation of the cyclic product is favored. In contrast, in the second reaction, ring-opening is favored due to the high ring strain associated with cyclobutene formation.
Voltaic/Galvanic Cells
Spontaneous Chemical Reactions
Spontaneous redox reactions occur abundantly in nature. The chemical reaction occurring in a disposable AA battery powering our remote controls is one such example of a spontaneous redox reaction. Another example is the immersion of coiled copper wire into an aqueous silver nitrate solution. The reaction shows a gradual, visually impressive color change from colorless to bright blue and the formation of a grey precipitate on the copper wire. In this experiment,...
Spontaneous redox reactions occur abundantly in nature. The chemical reaction occurring in a disposable AA battery powering our remote controls is one such example of a spontaneous redox reaction. Another example is the immersion of coiled copper wire into an aqueous silver nitrate solution. The reaction shows a gradual, visually impressive color change from colorless to bright blue and the formation of a grey precipitate on the copper wire. In this experiment,...
Photochemical Electrocyclic Reactions: Stereochemistry
The absorption of UV–visible light by conjugated systems causes the promotion of an electron from the ground state to the excited state. Consequently, photochemical electrocyclic reactions proceed via the excited-state HOMO rather than the ground-state HOMO. Since the ground- and excited-state HOMOs have different symmetries, the stereochemical outcome of electrocyclic reactions depends on the mode of activation; i.e., thermal or photochemical.
Selection Rules: Photochemical Activation
Selection Rules: Photochemical Activation
The Photochemical Reaction Center
Reaction centers are pigment-protein complexes that initiate energy conversion from photons to chemical entities. Therefore, photochemical reaction center is a more appropriate term that describes these complexes. The Nobel laureates Robert Emerson and William Arnold provided the first experimental evidence of photochemical reaction centers by demonstrating the participation of nearly 2,500 chlorophyll molecules for the release of just one molecule of oxygen. Despite thousands of photosynthetic...
Photoelectric Effect
When light of a particular wavelength strikes a metal surface, electrons are emitted. This is called the photoelectric effect. The minimum frequency of light that can cause such emission of electrons is called the threshold frequency, which is specific to the metal. Light with a frequency lower than the threshold frequency, even if it is of high intensity, cannot initiate the emission of electrons. However, when the frequency is higher than the threshold value, the number of electrons ejected...
Cycloaddition Reactions: MO Requirements for Photochemical Activation
Some cycloaddition reactions are activated by heat, while others are initiated by light. For example, a [2 + 2] cycloaddition between two ethylene molecules occurs only in the presence of light. It is photochemically allowed but thermally forbidden.


