According to the principle of electron transfer dynamicsμ＜0( μ =E~s*/s+-E~CB ) in heterogeneous systems, the therodynamics of electron transfer fron 13-SO~3Na-DDNA*( sodium salt of 14- dehyroxy - 15- deacetyl -hypocrellin A-13-sulfonate, an aqua soluble perylenequnone deruvative ) to the conductor band of CdS sol in our CdS-(13-SO~3Na-DDNA) complex is allowed. 13-SO~3Na- DDNAadsorbed strongly on colloidal CdS with an apparent association constant K~app of 1480(mol/L)^-1 determined by fluorescence quenching method. Using TEMPO( 2,2,6,6- tetramethyl - 1- piperdinyloxy), a stable free radical, as the electron acceptor, the kinetics of the photoinduced reduction reaction taking place on the surface of CdS colloidal particles was studied by the electron spin resonance method. The reaction order of TEMPO is zero and different from that of spin elimination reaction in a homogeneous systems such as HA( hyporcrellin A). By comparing rate constants, it is discovered that the (13-SO~3Na-DDNA) complex system is 82 time more efficient than CdS sol in photoreduction of TEMPO under the same visible light condition. The results show that the aqua soluble photosensitizer (13- SO~3Na-DDNA) has efficient photosensitization action on CdS colloidal semiconductor. It suggests that 13-SO~3Na-DDNA can be used as the efficient sensitizer of aolloidal semiconductor in the application of solar energy.

Key words: DERIVATIVES, CADMIUM SULFIDE, PHOTOINDUCED, PHOTOCATALYSIS, PHOTOSENSITIZATION