Sunlight-Driven Potassium Ion-Intercalated Nanozyme for Efficient Photofuel Cell Construction and Environmental Pollutant Detection

Although photo fuel cells (PFCs) can convert clean solar energy into electricity, they still find it difficult to meet the needs of increasing practical applications due to their limited efficiency. In this work, an ingenious dual-photoelectrode PFC was designed based on the heterojunction composed of K⁺ intercalation graphitic carbon nitride (AKCN) nanozyme and Ti-Fe-O nanotubes. The AKCN nanozyme was introduced into the photocathode innovatively to catalyze cheap glucose fuel efficiently, which increases the maximum output power of the PFCs by 5 times (16.4 μW cm^-2) and the open circuit potential by 1.5 times (0.834 V). The <i>in situ</i> FT-IR analysis confirmed the mechanism of glucose oxidation to gluconic acid, and calculations further proved that AKCN has better catalytic performance than g-C₃N₄. Meanwhile, by introducing <i>in situ</i> molecular imprinting technology into the photocathode, the detection of picomole-level pollutants was realized. Promising theoretical guidance has therefore been provided for improving PFCs' energy utilization efficiency and pollutants' detecting accuracy.