A major solar energy challenge is the goal of artificial synthesis in which sunlight is used to generate fuels or high energy chemicals. Natural photosynthesis uses solar energy to generate dioxygen and carbohydrates from carbon dioxide and water, but the targets of artificial photosynthesis can be more diverse. Our vision is to create a solar nano-device which will drive the coupled photo-conversion of methane and carbon dioxide into methanol and carbon monoxide respectively. This challenging target differs fundamentally from the familiar one of splitting water into hydrogen and oxygen. Our target offers products both on the oxidation and the reduction sides that are significant fuels or feedstocks. The photocatalytic reduction of CO2 and oxidation of alkanes represent long-standing goals of great complexity, but we base our concepts on well-established principles. We break down the goals into individual components, each of which is highly challenging within its own right and delivery of each would constitute a major breakthrough. The challenges will be met by a team of scientists, integrated across the four centres of Manchester, Nottingham, York and Norwich, who lead teams with expertise in photophysics, nanoscience, photochemistry, electrochemistry and synthesis. Thus these researchers will seek to establish the science required to underpin technologies that will allow the conversion of abundant and environmentally damaging feedstocks into products of high economic value by constructing a new class of solar device capable of driving green chemical reactions.