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hushaozheng

金虫 (小有名气)

[求助] 有关光催化剂p-n结问题,谁能帮解释一下?已有2人参与

最近看文献,是 关于BiOI-C3N4异质结催化剂的,有这么一段话,原文如下:

When p-type BiOI and n-type p-g-C3N4 are in contact, since the CB potential of p-g-C3N4 is more negative than that of BiOI, the electrons will diffusion from p-g-C3N4 to BiOI, resulting in accumulation of negative charges in BiOI close to the junction. At the same time, the holes transfer from BiOI top-g-C3N4, leaving a positive section in p-g-C3N4 near the junction. With equilibration of BiOI and p-g-C3N4 Fermi levels, the diffusion of electrons from p-g-C3N4 to BiOI stops. Meanwhile, the energy bands of BiOI shift upward along the Fermi level (EFp) and those of the p-g-C3N4 shift downward along its Fermi level (EFn), as shown in Fig. 9b. As a result, the CB bottom of BiOI became higher than that of p-g-C3N4. Under visible-light irradiation, both BiOI and p-g-C3N4 absorb photons of energy greater than the corresponding band gap energy, which excite the electrons in the VB to the CB and leave holes in the VB. The electrons in the conduction band of the p-BiOI are then transferred to the n-type p-g-C3N4, and the holes remain in the valence band of BiOI. The migration of photogenerated carriers can be promoted by the inner electric field established at the heterojunction interfaces.

我理解大概是这个意思:C3N4的导带比BiOI的导带更负,电子从C3N4传递到BiOI,价带BiOI比C3N4更正,所以空穴从BiOI传向C3N4,当达到某种平衡后,价带和导带位置会发生变化,使情况正好相反,电子从BiOI传递到C3N4,空穴从C3N4传向BiOI。这是为什么呢?有没有大牛能给系统又简明直白的解释一下,谢谢!
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whitetong

木虫 (正式写手)

【答案】应助回帖


liwentao2010: 金币+1, 谢谢回帖,欢迎常来交流 2014-11-23 09:51:29
如果他没有证据,就凭空说两者费米能级平衡后,BiOI导带比g-C3N4高,电子流向就发生了改变我觉得是站不住脚的,楼主可以发个邮件过去问一问的,或者看看好一点的期刊
8楼2014-11-23 08:34:17
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沙中木

金虫 (正式写手)

最近也被这种问题弄得头疼,希望有高人解释,让我理解深刻些。另外,楼主能否将文章题目告诉我一下,我好再学习学习。
顶!
路是由人走出来的
2楼2014-03-04 17:43:39
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hushaozheng

金虫 (小有名气)

引用回帖:
2楼: Originally posted by 沙中木 at 2014-03-04 17:43:39
最近也被这种问题弄得头疼,希望有高人解释,让我理解深刻些。另外,楼主能否将文章题目告诉我一下,我好再学习学习。
顶!

Dalton Trans., 2013, 42, 15726–15734 你看看吧 希望能看懂 然后再告诉我 呵呵
3楼2014-03-04 19:05:30
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hushaozheng

金虫 (小有名气)

引用回帖:
2楼: Originally posted by 沙中木 at 2014-03-04 17:43:39
最近也被这种问题弄得头疼,希望有高人解释,让我理解深刻些。另外,楼主能否将文章题目告诉我一下,我好再学习学习。
顶!

Dalton Trans., 2013, 42, 15726–15734  你看看吧 看懂了再告诉我 呵呵
4楼2014-03-04 19:05:58
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