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Deep ultraviolet photodetectors play a critical role in applications such as ozone layer monitoring and missile alert systems. This work investigates the potential of graphene quantum dots to enhance deep ultraviolet light photodetection within the graphene/Si heterojunction. The addition of graphene quantum dots not only reduces the Schottky barrier between graphene and Si but also enhances the absorption ability of deep ultraviolet light by graphene and Si. As a result, the modified junction exhibited exceptional performance metrics, including a notable responsivity of 0.21 A/W, an impressive specific detectivity of ${1}.{13}\times {10} ^{{11}}$ Jones, substantial external quantum efficiency of 94.5 %, and swift response speed (23.7/47.4 ns). Elevating the reverse bias voltage increases electron kinetic energy, thereby inducing collision ionization effects in Si. Subsequent evaluations revealed a high responsivity value of 31.4 A/W and a good gain of 28, affirming the capability of the device to detect faint light signals. The successful utilization of the Gr QDs/Gr/Si heterojunction as a single-pixel imaging device underscored its prowess in imaging applications. This innovative hybrid approach opens avenues for large-scale fabrication and diverse applications in optoelectronic devices.

Charged nanocellulose (NC) with a high aspect ratio (larger than 100) extracted from animal or bacterial cellulose and chemical cross-linked NC aerogels have great promising applicability in material science, but facile fabrication of such NC aerogels from plant cellulose by physical cross-linking still remains a major challenge. In this work, carboxylated cellulose nanofiber (CNF) with the highest aspect ratio of 144 was extracted from wasted ginger fibers by a simple one-step acid hydrolysis. Our approach could easily make the carboxylated CNF assemble into robust bulk aerogels with tunable densities and desirable shapes on a large scale (3D macropores to mesopores) by hydrogen bonds. Excitingly, these CNF aerogels had better compression mechanical properties (99.5 kPa at 80% strain) and high shape recovery. Moreover, the CNF aerogels had strong coagulation–flocculation ability (87.1%), removal efficiency of MB dye uptake (127.73 mg/g), and moderate Cu2+absorption capacity (45.053 mg/g), which were due to assistance mechanisms of charge neutralization, network capture effect, and chain bridging of high aspect ratio carboxylated CNF. This provided a novel physical cross-linking method to design robust aerogels with modulated networked structures to be a general substrate material for industrial applications such as superabsorbent, flocculation, oil–water separation, and potential electrical energy storage materials.