【摘要】 提出一种用于SO₂监测的多孔硅光学传感方案,其原理是以光催化氢化硅烷化处理的多孔硅作为敏感材料,根据多孔硅光致发光峰猝灭程度与SO₂浓度间定量关系,实现SO₂传感。实验采用电化学方法将n型单晶硅腐蚀形成多孔硅并进行氢化硅烷化处理,获得敏感膜层;研究多孔硅发光特性、传感特性、选择性和稳定性。结果表明该多孔硅具有良好光致发光性能,在大气环境和碱性介质中稳定性较高;当SO₂体积分数为5×10-5².5×10-4时,多孔硅传感SO2的过程服从SternVolmer方程,其SternVolmer常数k为5×104;同时,体积分数为0.05的CO₂或NO以及体积分数为0.01的CO或NO₂对多孔硅光致发光峰强度无影响。用本法测定样品中SO₂含量,结果满意。更多还原

【Abstract】 An optical sensing method is proposed for monitoring the SO₂ concentration in environment. The method depends on the photoluminescence of a light-promoted hydrosilylation porous silicon which can be ^reversibly quenched by SO₂ gas. When the porous silicon is exposed to a SO₂ environment, its intensity of ^photoluminescence peak changes with the SO₂ concentration. The freshly etched porous silicon was formed by electrochemical anodization of n-type single crystal ^silicon wafers. In order to improve stability of porous ^silicon , the light-promoted hydrosilylation method was used to treat the freshly etched porous silicon. The ^photoluminescence , sensing performance, stability and specificity for porous silicon were studied. The ^experimental results show that the hydrosilylation porous silicon is provided with favorable photoluminescence and stability; when SO₂ concentration ranges from 5×10^-5 to 2.5×10^-4 （V/V）, the quenching process of porous silicon is in accord with Stern-Volmer equation, and the Stern-Volmer constant k is equal to 5×10^-4 . ^Moreover , the other gas such as N₂, CO₂（0.05,V/V）, NO（0.05,^V/V ）, CO（0.01,^V/V ）, NO₂（0.01,^V/V ） have no effect on photoluminescence of the porous silicon. The result demonstrates the feasibility of ^optical sensing methods based on photoluminescence quenching of hydrosilylation porous silicon for monitoring sulfur dioxide in environment.更多还原