Solar light is widely recognized as one of the most valuable renewable energy sources for the future. However, the development of solar-energy technologies is severely hindered by poor energy-conversion efficiencies due to low optical-absorption coefficients and low quantum-conversion yield of current-generation materials. Huge efforts have been devoted to investigating new strategies to improve the utilization of solar energy. Different chemical and physical strategies have been used to extend the spectral range or increase the conversion efficiency of materials, leading to very promising results. However, these methods have now begun to reach their limits. What is therefore the next big concept that could efficiently be used to enhance light harvesting? Despite its discovery many years ago, with the potential for becoming a powerful tool for enhanced light harvesting, the slow-photon effect, a manifestation of light-propagation control due to photonic structures, has largely been overlooked. This review presents theoretical as well as experimental progress on this effect, revealing that the photoreactivity of materials can be dramatically enhanced by exploiting slow photons. It is predicted that successful implementation of this strategy may open a very promising avenue for a broad spectrum of light-energy-conversion technologies.

BiVO4 nanoparticles in the 3DOM TiO2 inverse opal structure act as a sensitizer to absorb visible light and to transfer efficiently high energy electrons to TiO2 to ensure long lifetime of photogenerated charges and keep them well separated, explaining the extraordinarily high photocatalytic performance of 3DOM BiVO4/TiO2 nanocomposites.

Among the nanomedecine challenges, engineering nanomaterials able to combine imaging and multi-therapies is hugely needed to address issues of a personalized treatment. In that context, a novel class of drug releasing and remotely activated nanocomposites based on carbon-based materials coated with mesoporous silica and loaded with an outstanding level of the anti-tumoral drug doxorubicin (DOX) has been designed. Such nanocomposites are shown able thus to combine drug delivery, phototherapy and imaging, thanks to the carbon based materials. First, carbon nanotubes (CNTs) and graphene sheets (called "few layer graphene" FLGs) are processed to afford a distribution size that is more suitable for nanomedicine applications. Then, the controlled coating of mesoporous silica (MS) shell having a thickness tailored with the sol-gel parameters (amount of precursor, sol-gel time) around the sliced CNTs and exfoliated FLGs are reported. Furthermore, the drug loading in such mesoporous nanocomposites is investigated in full and the surface modification with an aminopropyltriethoxysilane (APTS) coating leading to a controlled polysiloxane layer provides an ultra-high payload of DOX (up to 3 folds the mass of the composites). Such new