Due to the diurnal cycle of solar energy, a key for successful solar utilization is the development of an inexpensive storage mechanism, which represents a significant challenge. The smallest-volume in which electrons can be stored is in a chemical bond. Among them, hydrogen gas possesses a high energy density of 140 MJ/kg (9.17 MJ/L at 700 bar), making it a promising target for large scale energy storage and distribution. Therefore, the sunlight-triggered hydrogen evolution reaction (HER) represents a promising solution to worldwide consumption of fossil fuels. Current challenges in the field are related to the regeneration of the photosensitizer after the photoinduced electron transfer event. Indeed, most of reported HER rely on the use of sacrificial electron donors (triethylamine, triethanolamine…) which, after regenerating the photosensitizer, will be degraded and do not lead to any valuable products. With the idea of taking advantage of the photosensitizer regeneration event, researchers have developed systems using halides (X–) as the electron donor that will ultimately yield a covalent X-X bond after X– oxidation. During this Ph.D. thesis, we first explored the potential of new Ir(III) photosensitizers towards solar fuels production applications. Our objective was to develop Ir(III) photosensitizers that absorb a wider range of the solar spectrum, allowing hydrogen production upon blue to red light irradiation. Then, we focused on photoinduced halide oxidation by modifying the chemical structure of the ligands chelated not only onto Ir(III) but also with Ru(II) and Os(II) metal centers in order to increase their photo-oxidizing power while keeping convenient light absorption properties. Finally, photosensitizers based on Fe(III), a first row abundant transition metal, were investigated for halide oxidation applications.