Paper-Based Flexible and Photosensitive Electrodes for Electrochemical Hydrogen Evolution

We report the fabrication of a flexible and photosensitive electrode for electrocatalysis using efficient, robust, and photosensitive two-dimensional molybdenum disulfide (2D-MoS2) nanosheets and flexible, lightweight, large area, and conducting Ag-metal coated cellulose paper. The MoS2/Ag electrode shows a electrocatalytic activity with an overpotential of −250 mV versus the reversible hydrogen electrode (vs RHE) at a cathodic current density of −10 mA/cm2 because of the low charge transfer resistance. The electrode exhibits stability upto 17 h at a high cathodic current density of ≈ −44 mA/cm2 at −400 mV versus RHE. The MoS2/Ag cathode shows enhanced hydrogen evolution reaction activity under visible light and facilitates a faster catalytic reaction with an overpotential as low as −190 mV versus RHE. The photosensitive cathode demonstrates self-powered photodetection ability in acidic medium because of the optimized interaction of the OH/surface active sites and the presence of a built-in electric field at the MoS2/Ag interface. Overall, the present finding on flexible electrodes for electrocatalysis advocates the upsurge of applications of photosensitive electrodes in clean energy generation.