The scale-up of photoelectrochemical water splitting and CO2 reduction is currently hindered by the excessive band gap of metal oxide photoanodes. Metal sulfides 2D nanostructured morphology offer improved optoelectronic properties and catalytic capabilities in the oxygen evolution reaction (OER). This study demonstrates for the first time visible spectra absorption capabilities of SnxSy photoanodes, fabricated by facile non-vacuum techniques and post-annealed in a sulfur atmosphere, yielding SnS2 multilayer nanosheets with visible-light absorption down to 900 nm wavelengths. Optimal annealing (500 °C) resulted in >1 V photovoltages, photocurrents surpassing 1.6 mA/cm2 at 1.23VRHE, incident photon-to-current conversion efficiency (IPCE) of 75% at 330 nm. Photon conversion in the 500–900 nm range (down to 1.37 eV) is correlated with phase transformation from orthorhombic α-SnS to Sn2S3 and further hexagonal SnS2. IPCE is key for describing effective phase transformation and photon conversion at wavelengths below the dominant direct band gap for the SnS2, suggesting potential indirect transitions or confinement in the low-dimensional nanosheets. SnS2 nanosheets fabricated by solution-processed means, hold great potential for large-scale, cost-effective, and efficient photoelectrochemical devices.