ARTICLE This journal isHierarchically porous carbons (HPCs) show great potentials in energy storage due to their high surface area as well as short ion transport path derived from the interconnected porous framework. However, most existing protocols highly rely on the nanocasting and soft -templating, which usually restrict the using of raw materials and thus industrial unfeasible. It still reminds a big challenge to build HPCs from crude biomass, which is abundant on the earth, through a simply one-pot approach. Inspired by leavening bread, we design a strategy to fabricate HPCs with three-dimensional (3D) hierarchical pores consisting of macro, meso, and micropores. The "leavening method" is conducted simply by mixing the biomass with KHCO3 followed by undergoing elevated temperature treatment. Besides the well-defined hierarchical structure, the as-prepared HPCs also exhibit notably large specific areas (up to 1893 m 2 g -1 ). It is noteworthy that this "leavening" strategy is widely applicable for most of biomass derivatives and biomass, including glucose, cellulose, chitin, starch, rice straw, bamboo, and etc. When evaluated as supercapacitor electrode materials in two-electrode test systems, the as-prepared HPCs exhibit an excellent electrochemical performance: specific capacitance of 253 F g -1 , almost no capacitance loss after 10 000 cycles.Scheme 1 Scheme diagram of the formation of Cx-LE: mixing the biomass with the "leavening" agents, followed by calcination under the insert gas for the synthesis of Cx-LE.A simple and universal methodology for carbon materials derived from biomass with hierarchical structure.

Porous carbon materials stemming from biomass have drawn increasing interest because of their sustainable properties. Cellulose, hemicellulose, and lignin are the three basic components of crude biomass, and were investigated to reveal their influence on the derived carbonaceous materials. Huge amounts of oxygen-containing functional groups in cellulose and hemicellulose tend to be eliminated as H 2 O, CO 2 , and CO and give micropores during pyrolysis, whereas lignin contains plentiful aromatic units which are chemically inert, and thus produce nonporous carbon materials. When the KHCO 3 was introduced during the pyrolysis process, the plentiful hydroxyl in cellulose and hemicellulose underwent dehydration condensation among different parent polymers, which are responsible for the formation of macroporous structure. By contrast, The β-O-4 bands in lignin experience homolysis and give rise to benzene-containing units, which finally result in carbon nanosheets. Furthermore, we demonstrated the mixture of cellulose, hemicellulose, and lignin can display a three-dimensional porous structure (containing macropores, mesopores, and micropores) when less than 50% of lignin is contained.

Reproducing ion channel–based neural functions with artificial fluidic systems has long been an aspirational goal for both neuromorphic computing and biomedical applications. In this study, neuromorphic functions were successfully accomplished with a polyelectrolyte-confined fluidic memristor (PFM), in which confined polyelectrolyte–ion interactions contributed to hysteretic ion transport, resulting in ion memory effects. Various electric pulse patterns were emulated by PFM with ultralow energy consumption. The fluidic property of PFM enabled the mimicking of chemical-regulated electric pulses. More importantly, chemical-electric signal transduction was implemented with a single PFM. With its structural similarity to ion channels, PFM is versatile and easily interfaces with biological systems, paving a way to building neuromorphic devices with advanced functions by introducing rich chemical designs.