Schottky Junction-Engineered Heterostructure for High-Efficient Light-Driven Ion Pumping

Development of efficient artificial light-driven ion pumps is crucial for solar energy harvesting, yet remains fundamentally constrained by severe carrier recombination in photoactive materials. To overcome this fundamental limitation, we design a carbon nitride-carbon nanotube composite membrane that utilizes an interfacial Schottky junction for enhanced charge separation. The charge-regulating behavior of Schottky junctions effectively inhibits photoinduced charge recombination, thereby augmenting charge density asymmetry across the membrane. The resulting robust built-in electric field significantly amplifies light-driven force beyond single-component systems. Under 200 mW cm^-2 illumination, the composite membrane demonstrates exceptional ion pumping performance, enabling reverse ion transport against a 2000-fold concentration gradient. Compared to homogeneous carbon nitride membranes, it exhibits a 233% enhancement in gradient tolerance and a 293% increase in power output. This work presents a Schottky junction engineering strategy for high-performance light-driven ion pumps, paving the way for advanced solar energy conversion and optoelectronic applications.