This work focused on the impacts of FeCl3 impregnation ratio on the properties of FeCl3-activated bermudagrass (BG)-derived biochars (IA-BCs), adsorption of sulfamethoxazole (SMX) onto IA-BCs and ...regeneration of SMX-spent IA-BC. Compared with the control BC (85.82 m2/g), IA-BCs made via pyrolysis with FeCl3 to BG mass ratio between 1 and 3 (1–3 g FeCl3/g BG) resulted in significantly enhancing surface area (1014–1035 m2/g), hydrophobicity, Fe content in IA-BCs (3.87–7.27%), and graphitized carbon. The properties of IA-BCs supported magnetic separation and higher adsorption (32–265 mg SMX/g BC) than the control BC (6–14 mg SMX/g BC) at various pH. Adsorption experiments indicated various adsorption mechanisms between SMX and IA-BCs via π-π EDA, hydrophobic interactions, and hydrogen bond with intraparticle diffusion limitation. The adsorption was also found to be spontaneous and exothermic. The IA-BC made at FeCl3 to BG mass ratio of 2 (IA-BC2.0) showed the maximum adsorption capacity for SMX (253 mg SMX/g BC) calculated from Langmuir isotherm model. Additionally, both NaOH desorption and thermal oxidation showed effective regeneration of SMX-saturated IA-BC2.0 over multiple cycles. After three cycles of adsorption-regeneration, 64% and 62% of regeneration efficiencies were still achieved under thermal treatment at 300 °C and desorption with 0.1 M NaOH solution, respectively, indicating a cost-efficient adsorbent for the elimination of SMX in water.
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•Iron-activated bermudagrass (BG) biochars (BCs) were prepared.•Iron impregnation ratio affected the properties and adsorption capacity of BCs.•Iron impregnation ratio (FeCl3/BG) of 2 showed highest adsorption of SMX.•Mechanisms included hydrogen bond, non-covalent π-π, and hydrophobic interactions.•The activated BG BC was effectively regenerated by NaOH and thermal desorption.
The present study reports alfalfa (one of most abundant hays in U.S)-derived biochar for effective removal of emerging contaminants in water for the first time. The physicochemical properties of ...alfalfa-derived biochar (AF-BC) made at various pyrolysis temperatures were investigated, and correlated with the adsorption of bisphenol A (BPA) and sulfamethoxazole (SMX) in water. The increase in pyrolysis temperatures from 350 °C to 650 °C for the pyrolysis of AF led to a drastic increase in surface area and carbonization with the loss of functional groups. The AF-derived biochar made at 650 °C showed much higher adsorption capacities for BPA and SMX than those made at 350–550 °C, mainly owing to the hydrophobic and π-π interactions supported by its high surface area and degree of carbonization. The adsorption isotherms fitted the Freundlich for BPA and Temkin models for SMX well, respectively. The adsorption capacities of AF 650 for BPA and SMX were higher than those of other biochars but lower than those of commercial activated carbon. The pH-dependent desorption for AF 650 showed high efficiency for SMX, but low efficiency for BPA indicating needs for alternative regeneration methods for BPA.
•Alfalfa-derived biochar (AF-BC) was used for removal of BPA and SMX in water.•Pyrolysis temperature affected property and adsorption of AF-BC for BPA and SMX.•Adsorption of AF-BC at 650 °C for BPA and SMX was higher than other BCs.•Adsorption of BPA and SMX on AF-BC followed Freundlich and Temkin models.•Major mechanisms included hydrophobic and π-π interactions.
Abstract
The pure Kitaev honeycomb model harbors a quantum spin liquid in zero magnetic fields, while applying finite magnetic fields induces a topological spin liquid with non-Abelian anyonic ...excitations. This latter phase has been much sought after in Kitaev candidate materials, such as
α
-RuCl
3
. Currently, two competing scenarios exist for the intermediate field phase of this compound (
B
= 7 − 10 T), based on experimental as well as theoretical results: (i) conventional multiparticle magnetic excitations of integer quantum number vs. (ii) Majorana fermionic excitations of possibly non-Abelian nature with a fractional quantum number. To discriminate between these scenarios a detailed investigation of excitations over a wide field-temperature phase diagram is essential. Here, we present Raman spectroscopic data revealing low-energy quasiparticles emerging out of a continuum of fractionalized excitations at intermediate fields, which are contrasted by conventional spin-wave excitations. The temperature evolution of these quasiparticles suggests the formation of bound states out of fractionalized excitations.
•Pinus taeda-derived activated biochar was used for removal of tetracycline.•Possible adsorption mechanisms were explained by kinetic and isotherm studies.•Significant increase in adsorption capacity ...was achieved after NaOH activation.•Intraparticle diffusion would be the major limitation for the adsorption.•Adsorption capacity of activated BC was compared to commercial activated carbons.
The objective of this study was to evaluate the adsorption of tetracycline (TC) on the Pinus taeda-derived activated biochar (BC). After NaOH activation, the well-developed porous surface structure was observed with a significantly increase in surface area (959.9 m2/g). The kinetic and isotherm studies indicated that hydrogen bonding and π-π interaction on the heterogeneous surface would be the possible mechanisms, while intra-particle diffusion was considered as the major limitation for the adsorption of TC on the activated BC. The maximum adsorption capacity of the activated BC (274.8 mg TC/g BC) was higher than those of various activated BCs from the previous studies while it was similar to those of commercial activated carbons. It indicated that the activated BC had the high potential for TC removal in water.
To replace the conventional chemical bath deposition method, which is time‐consuming and has a high impurity level, a chemical single‐step deposition process employing a S/Sb ratio‐controlled ...SbCl3‐thiourea complex solution is introduced to load Sb2S3 into a mesoporous TiO2 electrode. This technique enables the fabrication of efficient and reproducible Sb2S3‐sensitzed inorganic–organic heterojunction hybrid solar cells with hole‐conducting conjugated polymers. The most efficient cell exhibits a short‐circuit current density of 16.1 mA cm−2, an open circuit voltage of 595.5 mV, and a fill factor of 66.5%, yielding a power conversion efficiency of ≈6.4% at standard AM1.5G condition (100 mW cm−2).
A single‐step solution approach based on SbCl3‐thiourea complex solution processing is introduced for high‐efficiency Sb2S3‐sensitized solar cells. The Sb2S3 is easily deposited on substrates using S/Sb‐ratio‐controlled SbCl3‐thiourea complex solution. The champion device exhibits an overall power conversion efficiency of 6.4% under standard 1.5G conditions.
Metasurfaces provide opportunities for wavefront control, flat optics, and subwavelength light focusing. We developed an imaging-based nanophotonic method for detecting mid-infrared molecular ...fingerprints and implemented it for the chemical identification and compositional analysis of surface-bound analytes. Our technique features a two-dimensional pixelated dielectric metasurface with a range of ultrasharp resonances, each tuned to a discrete frequency; this enables molecular absorption signatures to be read out at multiple spectral points, and the resulting information is then translated into a barcode-like spatial absorption map for imaging. The signatures of biological, polymer, and pesticide molecules can be detected with high sensitivity, covering applications such as biosensing and environmental monitoring. Our chemically specific technique can resolve absorption fingerprints without the need for spectrometry, frequency scanning, or moving mechanical parts, thereby paving the way toward sensitive and versatile miniaturized mid-infrared spectroscopy devices.
Realizing arbitrary manipulation of optical waves, which still remains a challenge, plays a key role in the implementation of optical devices with on‐demand functionalities. However, it is hard to ...independently manipulate multiple dimensions of optical waves because the optical dimensions are basically associated with each other when adjusting the optical response of the devices. Here, the concise design principle of a chiral mirror is utilized to realize the full‐dimensional independent manipulation of circular‐polarized waves. By simply changing three structural variables of the chiral mirror, the proposed design principle can arbitrarily and independently empower the spin‐selective manipulation of amplitude, phase, and operation wavelength of circular‐polarized waves with a large modulation depth. This approach provides a simple solution for the realization of spin‐selective full‐dimensional manipulation of optical waves and shows ample application possibilities in the areas of optical encryption, imaging, and detection.
A new design principle of chiral mirrors is proposed to realize full‐dimensional independent manipulation of circular‐polarized waves. By simply changing three structural variables of the chiral mirrors, the proposed design principle can arbitrarily and independently empower the spin‐selective manipulation of amplitude, phase, and operation wavelength of circular‐polarized waves with a large modulation depth.
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•Nanosized SnO2 photocatalysts were prepared with a precipitation method.•SnO2 nanoparticles displayed high photocatalytic activities for the MB degradation.•OH radicals are the main ...active species in photocatalysis on the SnO2 nanoparticles.
Nanosized SnO2 photocatalysts were prepared with a precipitation method and were characterized by performing transmission electron microscopy (TEM), powder X-ray diffraction (XRD), and X-ray absorption spectroscopy (XAS). The powder XRD results revealed that the SnO2 nanoparticles have a typical tetragonal rutile (cassiterite) structure and the average crystallite size was found to be approximately 4.5nm by using the Debye–Scherrer equation. The prepared SnO2 nanoparticles consist of agglomerated particles with a mean diameter of around 4–5nm according to the analysis of TEM images. The XAS data confirmed that the prepared samples have cassiterite structures with tin oxidation state of +4. The prepared SnO2 nanoparticles were found to exhibit approximately 3.8 times higher activity than bulk SnO2 in the photodegradation of methylene blue. On the basis of a trapping experiment, we developed a possible mechanism for the photodegradation on SnO2 nanoparticles.
Abstract
By providing an effective way to leverage nonlinear phenomena in integrated devices, high-Q optical resonators have led to recent advances in on-chip photonics. However, developing ...fabrication processes to shape any new material into a resonator with extremely smooth surfaces on a chip has been an exceptionally challenging task. Here, we describe a universal method to implement ultra-high-Q resonators with any new material having desirable properties that can be deposited by physical vapor deposition. Using this method light-guiding cores with surface roughness on the molecular-scale are created automatically on pre-patterned substrates. Its efficacy has been verified using As
2
S
3
, a chalcogenide glass that has high-nonlinearity. The Q-factor of the As
2
S
3
resonator so-developed approached the propagation loss record achieved in chalcogenide fibers which were limited by material losses. Owing to the boosted Q-factor, lasing by stimulated Brillouin scattering has been demonstrated with 100 times lower threshold power than the previous record.
•Effects of manure-derived biochar on anaerobic digestion of manure were investigated.•Biochar addition increased maximum methane production rate and potential.•Biochar shortened the lag phase of ...anaerobic digestion (AD).•Alkaline content in the manure biochar played a significant role in AD of manure.
Effects of dairy manure-derived biochar (M-BC) on methane production in anaerobic digestion (AD) of dry dairy manure were investigated with three different concentrations of biochar (0, 1 and 10 g/L) and temperatures (psychrophilic, 20 °C; mesophilic, 35 °C; thermophilic, 55 °C). Compared with the AD without any biochar, the cumulative methane and yield in the AD with 10 g/L biochar were increased to 27.65% and 26.47% in psychrophilic, 32.21% and 24.90% in mesophilic and 35.71% and 24.69% in thermophilic digestions. The addition of M-BC shortened the lag phases of AD at all temperatures in the study while it lowered the concentration of total VFAs and propionic acid. It was suggested that the high nutrients and alkalinity potential of M-BC (i.e. 9.1% Ca, 3.6% Mg, 1.3% N, 0.14% P) would play significant roles in enhancing methane production and shortening lag phases from the AD of dairy manure.
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