Abstract: Novel magnesium dialkylaluminum alkoxide derivative represented by Mg[(.mu.--OR').sub.2 AlR.sub.2 ].sub.2 wherein R and R' are each a C.sub.1-5 alkyl group and R is not the same as R', preferably magnesium dimethylaluminum isopropoxide, is easily prepared by reacting a trialkylaluminum with an alcohol or an aluminum trialkoxide to obtain a dialkylaluminum alkoxide; reacting the dialkylaluminium alkoxide with an alkali metal alkoxide to obtain an alkali metal dialkylaluminum alkoxide; and reacting the alkali metal dialkylaluminum alkoxide with a magnesium halide. The alkoxide derivative of the present invention can be vaporized at a low temperature, below 70.degree. C. and, therefore, effectively employed in the CVD process of a magnesium aluminate film.

Abstract: The present invention relates to a photocatalyst for producing hydrogen, harmless to the environment and by which a large quantity of hydrogen is efficiently produced at low temperatures without using any organic promoter, represented by the following formula:Cs(a)X(c)/T(b)wherein "a" represents a percentage by weight of impregnated Cs on the basis of the weight of a carrier, being limited up to 6.0; "X" is a promoter selected from Ni, Co and Fe; "c" represents a percentage by weight of the promoter on the basis of the total weight of Cs and the promoter, being limited up to 50.0; "T" is the carrier consisting of a zinc sulfide mixture comprising an inorganic compound and zinc sulfide with the molar ratio of zinc:sulfur ranging from 1:0.1 to 1:2.8; and "b" represents a percentage by weight of the inorganic compound on the basis of the total amount of the ZnS mixture, being limited up to 50.