A water treatment device comprising a clear container with lid surrounded by a solar reflector, and an insert in the form of a thin sheet or mesh permanently coated with titanium dioxide as a water sanitizing catalyst. The container is filled with non-potable water, covered with the lid, and placed in direct sunlight. Direct and reflected sunlight enters the water through the clear container and lid, where the sunlight's ultraviolet (UV) radiation and increased solar thermal heat disinfect the water. Further, the catalyst on the insert reacts with dissolved oxygen in the water to produce reactive oxygen species. These reactive species react with and decompose organic compounds in the water, and kill or inactivate pathogens. In addition, the reactive oxygen species further react with the water itself to produce additional free radical species, which also react with and decompose organic compounds and kill or inactivate pathogens.