Highly sensitive ion regulation enabled by photothermal wood nanochannels

Abstract

Light-induced intelligent ion regulation has received considerable attention in sensing, energy conversion, and separation. However, conventional methods for constructing ionic nanochannels in two-dimensional layered membranes usually face challenges with complex processing, poor stability, and difficultly in scalable assembly. Herein, we developed an ionic wood (I-wood) that enables sensitive photothermal-regulated ion transport through the deposition of MoS₂ nanosheets on the delignified wood cell walls. Under asymmetric light irradiation, the efficient light-to-heat conversion and low thermal conductivity of I-wood create a substantial temperature gradient, which provides sufficient driving force to regulate ion transport. The ions respond sensitively to light and can be controlled by adjusting both the irradiation intensities and positions. Effective regulation of ions is achieved even in high-concentration, acidic, and alkaline electrolyte solutions. Given its low-cost raw materials and sensitive ion regulation capabilities, I-wood provides a promising approach for light-controlling ionic circuits and light-induced ionic energy conversion.