Spatially Engineered NiAu Heterodimer-Decorated n-Si Photoanode for Efficient Solar-Driven Glucose Oxidation

Photoelectrochemical (PEC) solar-driven conversion of waste biomass into value-added chemicals offers a promising route toward sustainable development but remains limited by inefficient charge carrier utilization. Here, we rationally construct a spatially engineered NiAu heterodimer via a two-step deposition strategy guided by bond energy compatibility and lattice mismatch principles. The NiAu layer effectively modulates the interfacial barrier height, promoting carrier separation and transport while suppressing bulk recombination, while the introduction of glucose into the electrolyte facilitates hole injection at the photoanode/electrolyte interface. The synergistic optimization of the heterointerface architecture and electrolyte composition enables a record-low PEC oxidation onset potential of -0.20 V versus RHE. Further coupling with nitrite reduction on a Ru-doped Cu nanowire cathode achieves unbiased solar-driven synthesis of fructose and ammonia. This work establishes a generalizable interfacial-electrolyte coengineering framework to overcome carrier utilization bottlenecks, offering new opportunities for advancing high-efficiency, unbiased PEC platforms for solar chemical manufacturing.