Nano-Cu2O-loaded Paper: Green Preparation and High Visible Light Photocatalytic Performance for Formaldehyde Removal

The removal of formaldehyde (HCHO) from indoor air is of great importance to reduce health risks and improve indoor air quality. In this study, nano-Cu2O-loaded paper with superior photocatalytic activity under visible light for the removal of HCHO was fabricated through a green, simple, and fast in situ synthesis method. The optimum preparation conditions for nano-Cu2O-loaded paper were as follows: 2 g (oven-dry basis) cellulose fibers, CuSO4 dosage 8 g, NaOH dosage 1.6 g, temperature 80℃, 60 min for Cu2+ absorption, and 60 min for reaction. Under the optimum conditions, the Cu2O deposition ratio approached 30% and the nano-Cu2O-loaded paper exhibited a catalytic efficiency of approximately 97% for HCHO removal. The photocatalytic capacity of nano-Cu2O-loaded paper for HCHO removal had a positive correlation with the deposition ratio of nano Cu2O particles. Excellent antibacterial property of nano- Cu2O-loaded paper against Staphylococcus aureus and Escherichia coli was also confirmed. Moreover, nano-Cu2O-loaded paper was proven to be hydrophobic.

Coaxing Polysaccharide Granules into Supramolecular Biocolloidal Additives for Papermaking

In light of developments in polysaccharide-based sustainable processes involving supramolecular interactions,we herein present our findings pertaining to coaxing polysaccharide granules into functional supramolecular biocolloids.Translucent biocolloidal dispersions containing various forms of starch are facilely designable,essentially built upon complexation between disassembled native cornstarch granules and amphiphilic ligands.Oily moieties of guest molecules are dynamically attractable into cavities of helical structures,with cationic groups pointing toward the bulk phase.This noncovalent attraction can generate core-shell biocolloidal particles.The significantly higher gelatinizability of freeze-dried biocolloids in contrast to native cornstarch granules is attributable to complex formation,and a homogenous dispersion is readily formable at room temperature.Our results also show biocolloids'ligand-related antibacterial activity.The use of biocolloids as wet-end additives for biofiber assemblies(cellulosic paper)can enhance mechanical strength,fines retention,and filler bondability.Supramolecular biocolloids with positively charged,translucent,easily gelatinizable,antibacterial,and polysaccharide-bondable functionalities would find tailorable use in the paper industry.

Improving Electrochemical Performance of Cellulose Fiber-based Supercapacitor Electrode Using Polypyrrole-wrapped Iron Oxyhydroxide

Polypyrrole(PPy)@cellulose fiber-based composites have been widely investigated as electrode materials for use in flexible supercapacitors.However,they cannot readily provide high specific capacitance and cyclic stability owing to their inherent drawbacks,such as high resistance,Weber impedance,and volume expansion or collapse during charging/discharging.In this study,iron oxyhydroxide(FeOOH)is incorporated in the abovementioned composite to decrease the equivalent series resistance,charge transfer resistance,and Weber impedance,thereby enhancing electron transfer and ion diffusion,which results in superior electrochemical performance.The PPy-wrapped FeOOH@cellulose fiber-based composite electrode with the molar ratio of FeSO_(4) to NaBH4 of 1∶1 exhibits a high specific capacitance of 513.8 F/g at a current density of 0.2 A/g,as well as an excellent capacitance retention of 89.4% after 1000 cycles.