氢对纯铁钝化膜电子性质的影响

采用电化学、光电化学和交流阻抗等方法研究了氢对纯铁钝化膜形成过程和电子性质的影响。结果表明氢的存在会延长钝化膜的形成，增加稳态钝化条件下的溶解速率；氢能提高钝化膜光电流、降低禁带宽度；氢促使钝化膜的电容和掺杂浓度升高，并降低膜的平带电位。

EFFECT OF HYDROGEN ON ELECTRONIC PROPERTIES OF PASSIVE FILM ON PURE IRON

Pure iron membranes were pre-charged with hydrogen at various current densities. Effect of hydrogen on the film formation process on iron was studied by electrochemical methods. It showed that charged hydrogen delays the film formation and enhances the dissolution rate at passive state. After hydrogen injection and film formation at different passivation potentials, the AC impedance of the passive film has been measured. The results revealed that the capacitance and adulterated concentration of the film is increased, but the flat band potential is decreased by intrinsic hydrogen. Photoelectrochemical test indicated that hydrogen does not change the semiconductor types of the film, but enhances the photocurrent and reduces forbidden band gap. The results are discussed in relation to semiconductor model, and it was found that hydrogen influences the electronic properties mainly through changing the composition of passive film.