continuation of explanation about my research

 Yesterday, I explained my research background. Today, I want to write about continuation of my research. Particular, I will focus on photocatalyst. 
 I defined that the photocatalyst is substance which can cause redox reaction when light is irradiated. When were photocatalyst found? It was 1969 by Akira Fujishima. When he was a graduate student, he observed a phenomenon which hydrogen and oxygen were generated from water when light was irradiated to titanium dioxide electrode. The phenomenon was called "Honda-Fujishima effect" named after Akira Fujishima.  It has been 50 years since the phenomenon was found. However, it has not become available energy as a substitution of fossil fuel because we cannot produce hydrogen without additional energy like light, heat, and so on. The necessary points to realize hydrogen energy as usual is to produce hydrogen from water under visible light irradiation because sunlight contains visible light not ultraviolet light. This reason makes us impossible to utilize hydrogen energy.
 Thank you for reading my wrong sentence. Please comment on this article freely.