Dual-network MoS₂/PVA composite hydrogel synergized with hydrogen bond-borate ester bond toward high photoresponse and flexible adaptive photodetectors

Balancing high photoelectric response and flexible adaptability is a key research focus for MoS₂-based hydrogel photodetectors. In this study, a high-performance flexible MoS₂/polyvinyl alcohol (PVA) composite hydrogel photoelectrochemical (PEC) detector was successfully developed via constructing a synergistic dual network of hydrogen bonds and borate ester bonds. Hydrogen bonds formed between MoS₂ nanosheets and PVA effectively inhibit nanosheet agglomeration, thereby establishing continuous pathways for photogenerated carrier transport. Dynamic borate ester bonds formed between PVA and borax endow the device with outstanding flexible adaptability, including excellent stretchability, self-healing capability, and bending stability. Experimental results show that under a bias of 0.7 V and illumination intensity of 120 mW cm −2 , the device achieves a photocurrent density of 2.114 μA cm −2 . After 300% tensile strain, the photocurrent density only decreases by 25.9% compared to the unstretched state. Stable photoresponse is maintained across bending angles from 0° to 60°, and approximately 96.7% of the photoelectric performance is recovered after self-healing. This work clarifies the correlation between bonding interactions and photoelectric performance in flexible photodetectors, providing a novel design strategy for hydrogel-based flexible optoelectronic devices.