Search

Considerable efforts are being made to find cheaper and more efficient alternatives to the currently commercially available catalysts based on precious metals for the Hydrogen Evolution Reaction (HER). In this context, fullerenes have started to gain attention due to their suitable electronic properties and relatively easy functionalization. We found that the covalent functionalization of C60, C70 and Sc3N@IhC80 with diazonium salts endows the fullerene cages with ultra-active charge polarization centers, which are located near the carbon-diazonium bond and improve the efficiency towards the molecular generation of hydrogen. To support our findings, Electrochemical Impedance Spectroscopy (EIS), double layer capacitance (Cdl) and Mott-Schottky approximation were performed. Among all the functionalized fullerenes, DPySc3N@IhC80 exhibited a very low onset potential (-0.025 V vs RHE) value, which is due to the influence of the inner cluster on the extra improvement of the electronic density states of the catalytic sites. For the first time, the covalent assembly of fullerenes and diazonium groups was used as an electron polarization strategy to build superior molecular HER catalytic systems.

BACKGROUND Sickle cell disease (SCD) is a genetic red blood cell disorder associated with severe complications including chronic anemia, stroke, and vaso-occlusive crises (VOCs). VOCs are unpredictable, difficult to treat, and the leading cause of hospitalization. Recent efforts have focused on the use of mobile health technology to develop algorithms to predict pain in people with sickle cell disease. Combining the data collection abilities of a consumer wearable, such as the Apple Watch, and machine learning techniques may help us better understand the pain experience and find trends to predict pain from VOCs. OBJECTIVE The aim of this study is to (1) determine the feasibility of using the Apple Watch to predict the pain scores in people with sickle cell disease admitted to the Duke University SCD Day Hospital, referred to as the Day Hospital, and (2) build and evaluate machine learning algorithms to predict the pain scores of VOCs with the Apple Watch. METHODS Following approval of the institutional review board, patients with sickle cell disease, older than 18 years, and admitted to Day Hospital for a VOC between July 2021 and September 2021 were approached to participate in the study. Participants were provided with an Apple Watch Series 3, which is to be worn for the duration of their visit. Data collected from the Apple Watch included heart rate, heart rate variability (calculated), and calories. Pain scores and vital signs were collected from the electronic medical record. Data were analyzed using 3 different machine learning models: multinomial logistic regression, gradient boosting, and random forest, and 2 null models, to assess the accuracy of pain scores. The evaluation metrics considered were accuracy (F1-score), area under the receiving operating characteristic curve, and root-mean-square error (RMSE). RESULTS We enrolled 20 patients with sickle cell disease, all of whom identified as Black or African American and consisted of 12 (60%) females and 8 (40%) males. There were 14 individuals diagnosed with hemoglobin type SS (70%). The median age of the population was 35.5 (IQR 30-41) years. The median time each individual spent wearing the Apple Watch was 2 hours and 17 minutes and a total of 15,683 data points were collected across the population. All models outperformed the null models, and the best-performing model was the random forest model, which was able to predict the pain scores with an accuracy of 84.5%, and a RMSE of 0.84. CONCLUSIONS The strong performance of the model in all metrics validates feasibility and the ability to use data collected from a noninvasive device, the Apple Watch, to predict the pain scores during VOCs. It is a novel and feasible approach and presents a low-cost method that could benefit clinicians and individuals with sickle cell disease in the treatment of VOCs.

The synthesis, characterization and incorporation of fullerene derivatives bearing primary, secondary and tertiary nitrogen atoms, which possess different basicities, in perovskite solar cells (PSCs), is reported. In this work, we tested the compounds as conventional electron transporting materials (ETMs) in a single layer with phenyl-C61-butyric acid methyl ester (PC61BM) as control. Additionally, we tested the idea of separating the ETM into two different layers: a thin electron extracting layer (EEL) at the interface with the perovskite, and an electron transporting layer (ETL) to transport the electrons to the Ag electrode. The compounds in this work were also tested as EELs with C60 as ETL on top. Our results show that the new fullerenes perform better as EELs than as ETMs. A maximum power conversion efficiency (PCE) value of 18.88% was obtained for a device where a thin layer (∼3 nm) of BPy-C60 was used as EEL, a higher value than that of the control device (16.70%) with only pure C60. Increasing the layer thicknesses led to dramatically decreased PCE values, clearly proving that the compound is an excellent electron extractor from the perovskite layer but a poor transporter as a bulk material. The improved passivation ability and electron extraction capabilities of the BPy-C60 derivative were demonstrated by steady state and time-resolved photoluminescence (SS-and TRPL) as well as electrochemical impedance spectroscopy (EIS) and X-Ray photoelectron spectroscopy (XPS) measurements; likely attributed to the enhanced basicity of the pyridine groups that contributes to a stronger interaction with the interfacial Pb2+.

Fullerene-based low-dimensional (LD) heterostructures have emerged as excellent energy conversion materials. We constructed van der Waals 1T-MoS2/C60 0D-2D heterostructures via a one-pot synthetic approach for catalytic hydrogen generation. The interfacial 1T-MoS2-C60 and C60-C60 interactions as well as their electrocatalytic properties were finely controlled by varying the weight percentages of the fullerenes. 1T-MoS2 platforms provided a novel template for the formation of C60 nanosheets (NSs) within a very narrow fullerene concentration range. The heterostructure domains of 1T-MoS2 and C60 NSs exhibited excellent hydrogen evolution reaction (HER) performances, with one of the lowest onset potentials and ΔGH* values for LD non-precious nanomaterials reported to date.

Although noble metal nanocatalysts show superior performance to conventional catalysts, they can be problematic when balancing catalytic efficiency and reusability. In order to address this dilemma, we developed a smart paper transformer (s-PAT) to support nanocatalysts, based on easy phase conversion between paper and pulp, for the first time. The pulp phase was used to maintain the high catalytic efficiency of the nanocatalysts and the transformation to paper enabled their high reusability. Herein, as an example of smart paper transformers, a novel chromatography paper-supported Au nanosponge (AuNS/pulp) catalyst was developed through a simple water-based preparation process for the successful reduction of p-nitrophenol to demonstrate the high catalytic efficiency and reusability of the noble metal nanocatalyst/pulp system. The composition, structure, and morphology of the AuNS/pulp catalyst were characterized by XRD, TGA, FE-SEM, ICP, TEM, FT-IR, and XPS. The AuNS/pulp catalyst was transformed into the pulp phase during the catalytic reaction and into the paper phase to recover the catalysts after use. Owing to this smart switching of physical morphology, the AuNS/pulp catalyst was dispersed more evenly in the solution. Therefore, it exhibited excellent catalytic performance for p-nitrophenol reduction. Under optimal conditions, the conversion rate of p-nitrophenol reached nearly 100% within 6 min and the k value of AuNS/pulp (0.0106 s−1) was more than twice that of a traditional chromatography paper-based catalyst (0.0048 s−1). Additionally, it exhibited outstanding reusability and could maintain its high catalytic efficiency even after fifteen recycling runs. Accordingly, the unique phase switching of this smart paper transformer enables Au nanosponge to transform into a highly efficient and cost-effective multifunctional catalyst. The paper transformer can support various nanocatalysts for a wide range of applications, thus providing a new insight into maintaining both high catalytic efficiency and reusability of nanocatalysts in the fields of environmental catalysis and nanomaterials., A smart paper transformer supported nanocatalyst platform is developed based on the facile phase conversion between paper and pulp for both high-efficiency and high-reusability catalysis, with wide applications demonstrated by using Au nanosponge.

In this work, two new C70 isomers, α and β bis(2-(thiophen-2-yl)ethyl)-C70-fullerene mono-adducts (DTC70), were synthesized, characterized and used as electron transporting materials (ETMs) in perovskite solar cells (PSCs). Our results show that the α isomer improves both the Jsc and FF values of the devices, when compared to the results for the β-isomer and to those for phenyl-C70-butyric acid methyl ester (PC71BM), used as control. Devices based on α-DTC70 achieved a power conversion efficiency (PCE) of 15.9%, which is higher than that observed with PC71BM (15.1%).

The organization of specific pores in carbonaceous three-dimensional networks is crucial for efficient electrocatalytic processes and electrochemical performance. Therefore, the synthesis of porous materials with ordered and well-defined pores is required in this field. The incorporation of carbon nanostructures into polymers can create material structures that are more ordered in comparison to those of the pristine polymers. In this study we applied polymer-templated methods of carbon material preparation, in which outer blocks of the star copolymers form the carbon skeleton, while the core part is pore-forming. Well-defined 6

A new isolation protocol was recently reported for highly purified metallic Fullertubes D

The synthesis, characterization, and incorporation of phenyl-C61-butyric acid methyl ester (PC61BM)-like derivatives as electron transporting materials (ETMs) in inverted perovskite solar cells (PS...

In this work, two new C(70) isomers, α and β bis(2-(thiophen-2-yl)ethyl)-C(70)-fullerene mono-adducts (DTC(70)), were synthesized, characterized and used as electron transporting materials (ETMs) in perovskite solar cells (PSCs). Our results show that the α isomer improves both the J(sc) and FF values of the devices, when compared to the results for the β-isomer and to those for phenyl-C(70)-butyric acid methyl ester (PC(71)BM), used as control. Devices based on α-DTC(70) achieved a power conversion efficiency (PCE) of 15.9%, which is higher than that observed with PC(71)BM (15.1%).

Platinum (Pt)-based-nanomaterials are currently the most successful catalysts for the oxygen reduction reaction (ORR) in electrochemical energy conversion devices such as fuel cells and metal-air batteries. Nonetheless, Pt catalysts have serious drawbacks, including low abundance in nature, sluggish kinetics, and very high costs, which limit their practical applications. Herein, we report the first rationally designed nonprecious Co-Cu bimetallic metal-organic framework (MOF) using a low-temperature hydrothermal method that outperforms the electrocatalytic activity of Pt/C for ORR in alkaline environments. The MOF catalyst surpassed the ORR performance of Pt/C, exhibiting an onset potential of 1.06 V vs RHE, a half-wave potential of 0.95 V vs RHE, and a higher electrochemical stability (ΔE1/2 = 30 mV) after 1000 ORR cycles in 0.1 M NaOH. Additionally, it outperformed Pt/C in terms of power density and cyclability in zinc-air batteries. This outstanding behavior was attributed to the unique electronic synergy of the Co-Cu bimetallic centers in the MOF network, which was revealed by XPS and PDOS.

Fullerenes, the third allotropic form of carbon, have attracted considerable attention since they were first observed in 1985 and have been widely explored in the past three decades. In this chapter, we review the synthetic methods to prepare empty fullerenes as well as endohedral fullerenes; introduce the structural characteristics of fullerenes, including the isolated pentagon rule, topology, and naming according to the spiral algorithm, Stone-Wales transformations; and describe structures that have been characterized to date. In addition, general remarks about the most important aspects of the chemical reactivity, including hydrogenation, halogenation, oxidation, reduction, cycloaddition reactions, and nucleophilic, electrophilic, and radical additions are presented. Applications, such as in medical treatments and photovoltaic devices, are also systematically described.

Fullerene-based low-dimensional (LD) heterostructures have emerged as excellent energy conversion materials. We constructed van der Waals 1T-MoS

An emerging class of heterostructures with unprecedented (photo)electrocatalytic behavior, involving the combination of fullerenes and low-dimensional (LD) nanohybrids, is currently expanding the field of energy materials. The unique physical and chemical properties of fullerenes have offered new opportunities to tailor both the electronic structures and the catalytic activities of the nanohybrid structures. Here, we comprehensively review the synthetic approaches to prepare fullerene-based hybrids with LD (0D, 1D, and 2D) materials in addition to their resulting structural and catalytic properties. Recent advances in the design of fullerene-based LD nanomaterials for (photo)electrocatalytic applications are emphasized. The fundamental relationship between the electronic structures and the catalytic functions of the heterostructures, including the role of the fullerenes, is addressed to provide an in-depth understanding of these emerging materials at the molecular level.

Porous carbon encapsulated non-precious metal nanocatalysts have recently opened the ways towards the development of high-performance water remediation and energy conversion technologies. Herein, we report a facile, scalable and green synthetic methodology to fabricate porous carbon encapsulated transition metal nanocatalysts (M@TP: M = Cu, Ni, Fe and Co) using commercial tissue paper. The morphology, crystalline structure, chemical composition and textural properties of the M@TP nanocatalysts were thoroughly characterized. The catalytic activity of the M@TP nanocatalysts was investigated for the degradation of Congo red (CR) via peroxymonosulfate activation. Co@TP-6 was found to be the most active catalyst allowing 97.68% degradation in 30 min with a higher rate constant of 0.109 min−1. The nanocatalysts also displayed a carbon shell thickness-dependent electrocatalytic hydrogen evolution reaction (HER) activity, most likely due to the shielding effect of the carbon layers over the electron transfer (ET) processes at the metal core/carbon interfaces. Remarkably, the Ni@TP-6 electrocatalyst, with the smaller carbon shell thickness, showed the best electrocatalytic performance. They delivered an ultralow onset potential of −30 mV vs RHE, an overpotential of 105 mV at a current density of 10 mA·cm−2 and an excellent electrochemical stability to keep the 92% of the initial current applied after 25000 s, which is comparable with the HER activity of the state-of-the-art Ni-based catalysts.

Light induced charge separation in a newly synthesized triphenylamine-thiophene-Sc

Light induced charge separation in a newly synthesized triphenylamine–thiophene-Sc3N@Ih-C80 donor–acceptor conjugate and its C60 analog, triphenylamine–thiophene-C60 conjugate is reported, and the significance of the thiophene spacer in promoting electron transfer events is unraveled.

Here, we report the synthesis and characterization of crystalline C60 nanomaterials and their applications as bifunctional water splitting catalysts. The shapes of the resulting materials were tuned via a solvent engineering approach to form rhombic-shaped nanosheets and nanotubes with hexagonal close packed-crystal structures. The as-synthesized materials exhibited suitable properties as bifunctional catalysts for HER and ORR reactions surpassing by far the electrocatalytic activity of commercially available amorphous C60. The C60 nanotubes displayed the most efficient catalytic performance with a small onset potential of −0.13 V vs. RHE and ultrahigh electrochemical stability properties towards the generation of molecular hydrogen. Additionally, the rotating-disk electrode measurements revealed that the oxygen reduction mechanism at the nanotube electrochemical surfaces followed an effective four-electron pathway. The improved catalytic activity was attributed to the enhanced local electric fields at the high curvature surfaces.

The synthesis of new C60 fullerene derivatives functionalized with thiophene moieties as well as with electron donating or electron withdrawing groups, bromine (Br) or cyano (CN), respectively, using Bingel reactions is reported. The synthesized derivatives were used as the electron transporting materials (ETMs) in inverted perovskite solar cells (PSCs). Compared to devices fabricated with [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM), the new derivatives showed similar electrochemical properties and electron mobilities. However, PSCs based on the new derivatives synthesized in this work exhibited higher power conversion efficiencies (PCEs) than PC61BM based devices, which were ascribed to their better passivation ability, likely due to specific interactions between the fullerene addend and the perovskite layer surface. Devices based on the fullerene bearing the CN group exhibited an additionally improved efficiency due to the increased dielectric constant (er) of this derivative. These results show that the new functionalized fullerene derivatives can act as efficient ETMs in inverted PSCs.

Fullerene derivatives are known for their excellent electron transport properties, which can effectively serve as electron transport layers (ETLs) deposited from solution at low temperatures in perovskite solar cells (PSCs). However, it remains unclear how functional groups attached to the fullerene derivatives influence device performances. Herein, the performance of an ETL based on [6,6]-phenyl-C61 butyric acid 2-ethylhexyl ester (PC61BEH) was investigated. It was demonstrated that the branched alkyl chain of the fullerene derivative can highly influence the solubility, film morphology, passivation ability, ETL-perovskite contact, and electron extraction ability of the fullerene derivative. Overall device performance and stability are dependent on these characteristics. The results suggest that further design and improvement of fullerene-based PSCs performance may be possible through optimization of the addend structure and functionality.

In this review, we summarize recent advances that have resulted in fullerene-based high-efficiency perovskite solar cells (PSCs) by new processing methods of the perovskite films, by adding fullerenes as interfacial selective electron extraction layers and improving device stability or by incorporating fullerene derivatives to eliminate hysteretic behavior of both regular and inverted PSC structures. Finally, we outline some perspectives for further advancing PSCs for large-scale and commercial applications.

The synthesis, characterization, and incorporation of phenyl-C

The synthesis of new C(60) fullerene derivatives functionalized with thiophene moieties as well as with electron donating or electron withdrawing groups, bromine (Br) or cyano (CN), respectively, using Bingel reactions is reported. The synthesized derivatives were used as the electron transporting materials (ETMs) in inverted perovskite solar cells (PSCs). Compared to devices fabricated with [6,6]-phenyl-C(61)-butyric acid methyl ester (PC(61)BM), the new derivatives showed similar electrochemical properties and electron mobilities. However, PSCs based on the new derivatives synthesized in this work exhibited higher power conversion efficiencies (PCEs) than PC(61)BM based devices, which were ascribed to their better passivation ability, likely due to specific interactions between the fullerene addend and the perovskite layer surface. Devices based on the fullerene bearing the CN group exhibited an additionally improved efficiency due to the increased dielectric constant (ε(r)) of this derivative. These results show that the new functionalized fullerene derivatives can act as efficient ETMs in inverted PSCs.

Correction for ‘The role of fullerene derivatives in perovskite solar cells: electron transporting or electron extraction layers?’ by Olivia Fernandez-Delgado et al., J. Mater. Chem. C, 2021, DOI: 10.1039/D0TC05903J.

Herein, magnetic C@Fe nanocatalyst was prepared via the direct carbonization of Fe-BDC (benzene-1,4-dicarboxylic acid) metal organic framework and utilized for the catalytic reduction of 4-nitrophenol (4-NP) and methyl orange (MO). The nanocatalyst was characterized using VSM, TEM, SEM, EDS, FTIR, XRD and TGA instruments. The nanocatalyst showed excellent catalytic performance and good reusability. The calculated apparent rate constant was 1.34 min−1 and 0.92 min−1 for the 4-NP and MO reduction, which is higher than that of numerous previously reported nanocatalysts. Consequently, magnetically recoverable C@Fe nanocatalyst could be considered as a promising nanocatalyst due to their easy preparation and excellent activity.

Herein we report a simple, facile and green technique for the preparation of magnetic cobalt nanoparticles (NPs) embedded on porous carbon (C@Co) nanocatalyst using MOFs template and explored for the catalytic reduction of Methyl orange (MO) and 4-Nitrophenol (4-NP). The morphology, structure and composition of the nanocatalyst were characterized by using Scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), Transmission Electron Microscopy (TEM), X-ray diffraction (XRD), Raman spectroscopy, thermogravimetric analysis (TGA) and Vibrating Sample Magnetometer (VSM) techniques. XRD analysis confirmed the presence of metallic Co NPs as well as their high crystalline structure. TEM analysis revealed that all the Co NPs are wrapped and protected by the porous carbon matrix. Catalytic studies revealed that the prepared magnetic C@Co nanocatalyst could catalyze the reduction of MO and 4-NP in 2 min effectively. Furthermore, the nanocatalyst showed an outstanding reusability and recyclability characteristics that remained unchanged even after several cycles. Consequently, this research offers a highly active, recyclable and magnetically isolable nanocatalyst, which can be utilized for many catalytic industrial processes. In this regard, the magnetic C@Co nanocatalyst could be a potential candidate for the wastewater treatment.

Perovskite Solar Cells (PSCs) have experienced an incredible rise in power conversion efficiencies (PCEs) starting from 3.8% in 2009 to 22.1% in 2016. Due to their electron transporting properties and low cost deposition techniques, fullerene derivatives are the most attractive semiconductors used as electron transporting materials (ETMs) in PSCs. The most widely used fullerene in inverted planar perovskite solar cells is [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM), which exhibits high performance. Devices based on that compound have achieved a maximum PCE of 20.15%, reduced hysteresis, and improved stability. In our laboratories, PC61BM like fullerene derivatives were synthesized via Bingel reaction at room temperature in high yields and incorporated into PSCs as ETMs. It was demonstrated that the branched alkyl chain of the fullerene derivative can highly influence the solubility, film morphology, passivation ability, ETL-perovskite contact, and electron extraction ability of the fullerene derivative. Overall device performance and stability were improved compared to those devices based on PC61BM. Figure 1

This study investigated children's and adults' event recall accuracy and suggestibility effects when participants' accuracy motivation was manipulated. A total of 240 participants (6-, 7-, and 8-year-olds, and adults) were shown a video and later asked 4 types of questions: answerable questions, both open-ended and strongly misleading, and unanswerable questions, both open-ended and strongly misleading. Participants were either (a) rewarded with a token for every correct answer (high accuracy motivation, Free Report Plus Incentive condition), (b) explicitly given the option of answering with "don't know" when unsure (medium accuracy motivation, Free Report condition), or (c) asked to provide an answer to every question, even when they were not sure or had to guess or both (low accuracy motivation, Forced Report condition). The condition with the high accuracy motivation yielded the highest recall accuracy scores for answerable open-ended and misleading questions. For unanswerable questions, even the young...

The unique properties of organic-inorganic hybrid perovskite materials make them promising candidates for developing next-generation photovoltaic cells for commercial applications to compete with silicon solar cells. Inverted planar structure perovskite solar cells (PSCs), due to their low temperature precessing and lack of hysteretic problems, are attracting increased attention by researchers around the world. Fullerene derivatives are the most widely used electron transporting materials (ETMs) in inverted planar perovskite solar cells, especially [6,6]-phenyl-C61-butyric acid methylester (PC61BM), which exhibits very good performance. However, the influence of adducts on fullerene-based PSCs performance has not been fully explored to date. Here, new C60 and C70 fullerene derivatives were synthesized in high yields via Bingel reactions at room temperature and incorporated into CH3NH3PbI3 perovskite solar cells as electron transporting materials. Figure 1. Synthesis of C60 and C70 fullerene derivatives via Bingel reaction. Figure 1