Superior supercapacitive performance in porous nanocarbons

Porous nanocarbons with average particle size 20–40 nm were developed using biowaste oil palm leaves as a precursor.Simple pyrolysis was carried out at 700 °C under nitrogen atmosphere.Obtained porous nanocarbons showed excellent porous nature along with spherical shape.Symmetric supercapacitor fabricated from porous nanocarbons showed superior supercapacitance performance where high specific capacitance of 368 F/g at 0.06 A/g in 5 M KOH were reported.It also exhibited high stability(96% over 1700cycles) and energy density of 13 Wh/kg.Low resistance values were obtained by fitting the impedance spectra,thus indicating the availability of these materials as supercapacitors electrode.The presented method is cost effective and also in line with waste to wealth approach.

Potential Alzheimer’s disease therapeutic nano-platform: Discovery of amyloid-beta plaque disaggregating agent and brain-targeted delivery system using porous silicon nanoparticles

There has been a lot of basic and clinical research on Alzheimer’s disease(AD)over the last 100 years,but its mechanisms and treatments have not been fully clarified.Despite some controversies,the amyloid-beta hypothesis is one of the most widely accepted causes of AD.In this study,we disclose a new amyloid-beta plaque disaggregating agent and an AD brain-targeted delivery system using porous silicon nanoparticles(pSiNPs)as a therapeutic nano-platform to overcome AD.We hypothesized that the negatively charged sulfonic acid functional group could disaggregate plaques and construct a chemical library.As a result of the in vitro assay of amyloid plaques and library screening,we confirmed that 6-amino-2-naphthalenesulfonic acid(ANA)showed the highest efficacy for plaque disaggregation as a hit compound.To confirm the targeted delivery of ANA to the AD brain,a nano-platform was created using porous silicon nanoparticles(pSiNPs)with ANA loaded into the pore of pSiNPs and biotin-polyethylene glycol(PEG)surface functionalization.The resulting nano-formulation,named Biotin-CaCl2-ANA-pSiNPs(BCAP),delivered a large amount of ANA to the AD brain and ameliorated memory impairment of the AD mouse model through the disaggregation of amyloid plaques in the brain.This study presents a new bioactive small molecule for amyloid plaque disaggregation and its promising therapeutic nano-platform for AD brain-targeted delivery.

One-step preparation of porous aminated-silica nanoparticles and their antibacterial drug delivery applications

Porous functionalized silica nanoparticles have attracted the interest of researchers as they are excellent carriers for antibacterial drug delivery applications.In this work,porous aminated-silica nanoparticles(SiO2-NH2 NPs) were prepared via one-step approach through the ammonia-catalyzed hydrolysis of tetraethylorthosilicate(TEOS) and(3-aminopropyl) triethoxysilane(APTES) in a mixed water-ethanol system.The obtained SiO2-NH2 NPs displayed a spherical morphology and relatively uniform size distribution,while the morphology and structure of SiO2-NH2 NPs were mainly determined by the order of the reagents added and the pH value of the solution.After characterization,the results showed that there were a large number of-NH2 groups on the surface of porous SiO2-NH2 NPs and that the porous SiO2-NH2 NPs had a large surface area of 476 m2 g-1 with an average pore width of 4.3 nm.Through an absorbing-releasing experiment and bacterial test,those SiO2-NH2 NPs were found to exhibit efficient absorption and release of drugs as well as a pH-de pendent release pattern of epirubicin-loaded SiO2-NH2 NPs.Meanwhile,SiO2-NH2@capsaicin NPs exhibited antibacterial properties.Those porous SiO2-NH2 NPs could be a candidate for drug delivery for antibacterial applications owing to their tailored porous structure and high surface area.

Antiviral adsorption activity of porous silicon nanoparticles against different pathogenic human viruses

New viral infections,due to their rapid spread,lack of effective antiviral drugs and vaccines,kill millions of people every year.The global pandemic SARS-CoV-2 in 2019-2021 has shown that new strains of viruses can widespread very quickly,causing disease and death,with significant socio-economic consequences.Therefore,the search for new methods of combating different pathogenic viruses is an urgent task,and strategies based on nanoparticles are of significant interest.This work demonstrates the antiviral adsorption(virucidal)efficacy of nanoparticles of porous silicon(PSi NPs)against various enveloped and non-enveloped pathogenic human viruses,such as Influenza A virus,Poliovirus,Human immunodeficiency virus,West Nile virus,and Hepatitis virus.PSi NPs sized 60 nm with the average pore diameter of 2 nm and specific surface area of 200 m^(2)/g were obtained by ball-milling of electrochemically-etched microporous silicon films.After interaction with PSi NPs,a strong suppression of the infectious activity of the virus-contaminated fluid was observed,which was manifested in a decrease in the infectious titer of all studied types of viruses by approximately 104 times,and corresponded to an inactivation of 99.99%viruses in vitro.This sorption capacity of PSi NPs is possible due to their microporous structure and huge specific surface area,which ensures efficient capture of virions,as confirmed by ELISA analysis,dynamic light scattering measurements and transmission electron microscopy images.The results obtained indicate the great potential of using PSi NPs as universal viral sorbents and disinfectants for the detection and treatment of viral diseases.

Enhancement of R6G fluorescence by N-type porous silicon deposited with gold nanoparticles

By the electrochemical anodization method,we achieve the single-layer macroporous silicon on the N-type silicon,and prepare gold nanoparticles with sodium citrate reduction method. Through injecting the gold nanoparticles into the porous silicon by immersion,the fluorescence quenching mechanism of porous silicon influenced by gold nanoparticles is analyzed. Then the macroporous silicon deposited with gold nanoparticles is utilized to enhance the fluorescence of rhodamine 6G(R6G). It is found that when the macroporous silicon is deposited with gold nanoparticles for 6 h,the maximum fluorescence enhancement of R6G(about ten times) can be realized. The N-type porous silicon deposited with gold nanoparticles can be an excellent substrate for fluorescence detection.

Characterization of the nanosized porous structure of black Si solar cells fabricated via a screen printing process

A silicon（Si） surface with a nanosized porous structure was formed via simple wet chemical etching catalyzed by gold（Au） nanoparticles on p-type Cz-Si（100）.The average reflectivity from 300 to 1200 nm was less than 1.5%.Black Si solar cells were then fabricated using a conventional production process.The results reflected the output characteristics of the cells fabricated using different etching depths and emitter dopant profiles.Heavier dopants and shallower etching depths should be adopted to optimize the black Si solar cell output characteristics. The efficiency at the optimized etching time and dopant profile was 12.17%.However,surface passivation and electrode contact due to the nanosized porous surface structure are still obstacles to obtaining high conversion efficiency for the black Si solar cells.

TiO_2-modified nano-egg-shell Pd catalyst for selective hydrogenation of acetylene

Pd-based egg-shell nano-catalysts were prepared using porous hollow silica nanoparticles （PHSNs） as support, and the as-prepared catalysts were modified with TiO2 to promote their selectivity for hydro-genation of acetylene. Pd nanoparticles were loaded evenly on PHSNs and TiO2 was loaded on the active Pd particles. The effects of reduction time and temperature and the amount of TiO2 added on catalytic per-formances were investigated by using a fixed-bed micro-reactor. It was found that the catalysts showed better performance when reduced at 300 ℃ than at 500℃, and if reduced for 1 h than 3 h. When the amount of Ti added was 6 times that of Pd, the catalyst showed the highest ethylene selectivity.