Photochemical coproduction of hydrogen and chemicals from a wireless monolithic leaf

Artificial leaves integrating light absorption and catalysis provide a solution to the intermittency of renewable electricity by directly converting sunlight into fuels. Here, we design a wireless monolithic leaf that integrates a tunnel oxide passivating contact Si bottom absorber with a defect-controlled bismuth vanadate (BiVO₄) top absorber for photochemical coproduction of hydrogen and chemicals. The combination of nanoporous BiVO₄ and micropyramidal silicon ensures a high photovoltage by extending light harvesting through complementary band structures and geometric nanotexturing. A surface-reduced amorphous BiVO₄ shell rich in oxygen vacancies improves hole transport and catalytic activity for selective glycerol oxidation, enabling bias-free operation. As a standalone photochemical diode that builds on bias-free photoelectrocatalysis, the wireless monolithic leaf continuously coproduces hydrogen and C₃ chemicals solely under sunlight, achieving rates of 395.9 and 91.68 millimoles per square meter per hour. This work highlights absorber and interface engineering for efficient, durable artificial leaves toward sustainable hydrogen and value-added chemical production.