(i) This configured system can possibly facilitate the hydrogen (reduction reaction) evolution from water decomposition (ii) The effective of charge separation may account for the unusual photo activity for water decomposition especially for hydrogen evolution so far reported on TiO2 system (iii) The holes accumulated on Rutile core may facilitate oxygen evolution and possibly account for the non-stoichiometric amount of oxygen evolution observed experimentally. These authors have also proposed that the patterning of the photo-catalytic systems can selectively tune the properties of one of the components of the multi-component system by the various modes of sensitization (doping, metallization and other means of sensitization) and the structured configurations may also facilitate directional transfer of charges. A few other remarks are appropriate at this stage. Even though in this short presentation only titania system is considered, it may be equally applicable to other photo-catalytic and PEC systems. The generation of core shell configuration in titania systems have been attempted in a number of ways, like vapour phase hydrolysis ,as well as in caramelized sucrose (organic or inorganic) matrix followed 10 by hydrothermal process generating capped systems which ultimately yields the core shell configuration of the same component namely titania in this case. Since the introduction of these hetero atoms favours core shell configuration, it is natural systems prepared using the precursors containing hetero-atoms will exhibit increased photo-catalytic and PEC activity. Liu et al. have also claimed that the depth of the rutile core in the Anatase shell can be tuned by adjusting the thickness of TiOxXy (X being the hetero/metal atom and x< or > y). There can be alternate methods of generating core shell configurations. It may be possible that the presence of hetero atoms or metallic species may be inducing/retarding the phase transformation of anatase to rutile and the extent of these species inducing the phase transformation and the conditions employed may be responsible for this core shell configuration being formed in TiO2.