Ultrathin 2D molybdenum disulfide (MoS2), which is the flagship of 2D transition‐metal dichalcogenide nanomaterials, has drawn much attention in the last few years. 2D MoS2 has been banked as an ...alternative to platinum for highly active hydrogen evolution reaction because of its low cost, high surface‐to‐volume ratio, and abundant active sites. However, when MoS2 is used directly as a photocatalyst, contrary to public expectation, it still performs poorly due to lateral size, high recombination ratio of excitons, and low optical cross section. Besides, simply compositing MoS2 as a cocatalyst with other semiconductors cannot satisfy the practical application, which stimulates the pursual of a comprehensive insight into recent advances in synthesis, properties, and enhanced hydrogen production of MoS2. Therefore, in this Review, emphasis is given to synthetic methods, phase transitions, tunable optical properties, and interfacial engineering of 2D MoS2. Abundant ways of band edge tuning, structural modification, and phase transition are addressed, which can generate the neoteric photocatalytic systems. Finally, the main challenges and opportunities with respect to MoS2 being a cocatalyst and coherent light–matter interaction of MoS2 in photocatalytic systems are proposed.
A potential insight into synthesis methods, phase transitions, and tunable optical properties is reviewed for the rational design of MoS2 photocatalytic systems. Moreover, photocatalytic enhancements of plasmon‐assisted MoS2 are also reviewed to further explore the prospects for MoS2 as a cocatalyst and a photocatalyst.
Abstract
Here, an engineered tunneling layer enhanced photocurrent multiplication through the impact ionization effect was proposed and experimentally demonstrated on the graphene/silicon ...heterojunction photodetectors. With considering the suitable band structure of the insulation material and their special defect states, an atomic layer deposition (ALD) prepared wide-bandgap insulating (WBI) layer of AlN was introduced into the interface of graphene/silicon heterojunction. The promoted tunneling process from this designed structure demonstrated that can effectively help the impact ionization with photogain not only for the regular minority carriers from silicon, but also for the novel hot carries from graphene. As a result, significantly enhanced photocurrent as well as simultaneously decreased dark current about one order were accomplished in this graphene/insulation/silicon (GIS) heterojunction devices with the optimized AlN thickness of ~15 nm compared to the conventional graphene/silicon (GS) devices. Specifically, at the reverse bias of −10 V, a 3.96-A W
−1
responsivity with the photogain of ~5.8 for the peak response under 850-nm light illumination, and a 1.03-A W
−1
responsivity with ∼3.5 photogain under the 365 nm ultraviolet (UV) illumination were realized, which are even remarkably higher than those in GIS devices with either Al
2
O
3
or the commonly employed SiO
2
insulation layers. This work demonstrates a universal strategy to fabricate broadband, low-cost and high-performance photo-detecting devices towards the graphene-silicon optoelectronic integration.
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•Firstly report of Bi/BiOBr microspheres with dominant exposed (0 0 1) facets.•Superior performance of Bi/BiOBr-001-m over other BiOBr catalysts.•Synergistic effect of crystal ...structures engineering and doped Bi element.•Sensitization effect of adsorbed RhB for bettering photocatalyst property.
A facile one-step solvothermal process was used to synthesize Bi-doped BiOBr microspheres with mainly the (0 0 1) crystal facet exposed (Bi/BiOBr-001-m), which exhibited enhanced photocatalytic performance. The photocatalytic performance and stability of the obtained Bi/BiOBr-001-m photocatalyst for Cr(VI) photoreduction removal and rhodamine B (RhB) photooxidation degradation were significantly better than those of pure BiOBr and Bi-doped BiOBr microspheres. The enhanced performance is ascribed to the retarding effect of photoinduced electron–hole recombination caused by Bi doping and the predominant (0 0 1) crystal plane composite structure. The photocatalytic performance could be further boosted by the adsorbed RhB owing to the dye sensitization effect. This work provides a reference for effectively improving the photocatalytic performance by combining crystal facet engineering and element doping.
Background
Due to their rarity, the clinicopathological characteristics and prognostic factors of spinal cord gliomas are still unclear. Here, we aimed to clarify these issues in a cohort of 108 ...spinal cord astrocytomas.
Methods
We characterized the clinicopathological characteristics, including 2016 World Health Organization (WHO) grade, age, sex, location, segment length, resection, pre‐ and postsurgery, Modified McCormick Scale (MMS), radio‐ and chemotherapy, and Ki‐67 and H3 K27M mutations, in 108 spinal cord astrocytomas through heatmaps. The Cox regression analysis and Kaplan‐Meier curves were used to study the prognostic value of these clinicopathological features.
Results
There are a total 38 H3 K27M‐mutant tumors, including 31 cases with histological grade II/III tumors. The age of low‐grade astrocytoma patients (WHO grade I/II, n = 54) was significantly younger (27.0 vs 35.5 years, P = .001) than those with high‐grade tumors (WHO grade III/IV, n = 54). All patients underwent surgical resection with neurophysiological monitoring, and the surgery did not result in significant changes in MMS. The presurgery MMS was associated with overall survival in the high‐grade subgroup (P = .008) but not in the low‐grade subgroup (P = .312). While, the high content of resection improved the survival of only patients with low‐grade astrocytomas (P = .016) but not those with high‐grade astrocytomas (P = .475). Both the low‐grade and high‐grade astrocytomas had no obvious benefit from neither adjuvant chemotherapy nor radiotherapy (all P > .05).
Conclusions
We characterized the clinicopathological characteristics and their prognostic values in 108 spinal cord astrocytomas, which could help with evidence‐based management of spinal cord astrocytomas.
We characterized the clinicopathological characteristics and their prognostic values in 108 spinal cord astrocytomas, which could help with evidence‐based management of spinal cord astrocytomas.
Abstract
BACKGROUND
“Diffuse midline glioma, H3 K27M-mutant” (DMG) mainly arises within the pontine, thalamic, and spinal cord regions. Because of the rarity of spinal cord gliomas, the general ...knowledge surrounding DMGs is mainly based on pontine and thalamic gliomas, whereas tumor location tends to influence the clinicopathological features and prognosis.
OBJECTIVE
To determine the clinicopathological characteristics and molecular profiles of DMGs located in the spinal cord.
METHODS
The clinical and molecular pathologic features and prognosis were comprehensively analyzed in a series of 44 patients with spinal cord DMGs.
RESULTS
The median age was 36 yr, and 88.7% of patients (39/44) were adults (≥18 yr). Histopathologically, malignant grades included grade II (16 cases), grade III (20 cases), and grade IV (8 cases). Compared with patients with histological grade IV, patients with lower histological grade (grade II/III) were older (37 vs 24 yr, P = .020) and were associated with longer overall survival (24.1 vs 8.6 mo, P = .007). All 30 tested tumors were isocitrate dehydrogenase (IDH) wild type, and 96% of cases (22/23) presented with unmethylated O6-methylguanine-DNA methyltransferase. Univariate and multivariate analyses showed that histological grade and presurgery McCormick Scale scores were independent prognostic factors for overall survival, whereas extensive surgical resection and chemoradiotherapy were not significantly associated with improved survival. The most frequent anatomic locations were the cervical enlargement (C4-T1, n = 16) and conus medullaris (T12-L1, n = 13), which exhibited distinctive clinical characteristics and molecular features.
CONCLUSION
The findings provide guidelines for the evidence-based practice of the specialized management of spinal cord DMGs.
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•A highly efficient Fe SAs/NPs@NC catalyst for boosting the ORR is developed.•A synergistic effect stemming from the isolated Fe-Nx and metallic Fe is uncovered.•The catalyst showed ...high ORR activity and stability superior to the commercial Pt/C.•The Zn-air battery exhibits high power density and excellent cycling stability.
Herein, a proof-of-concept study on the evaluation of Fe nanoparticles (Fe NPs) encapsulated by nitrogen-doped carbon to Fe single atoms (Fe SAs) for boosting the oxygen reduction reaction (ORR) catalytic activity toward Zn-air batteries was reported. Specifically, unlike Fe SAs encapsulated by nitrogen-doped carbon (Fe SAs@NC), the Fe SAs and Fe NPs co-embedded in nitrogen-doped carbon (Fe SAs/NPs@NC) derived from a pyrolysis and acid dissolution protocols exhibits excellent ORR performance with good stability and remarkable methanol tolerance in alkaline solutions. Combining a series of experimental analyses, the strong interaction between the atomically dispersed Fe-Nx and adjacent Fe NPs in altering the electronic structure of isolated Fe-Nx sites could weaken the binding energies of the ORR intermediates on Fe SAs/NPs@NC, resulting in an enhanced electrocatalytic kinetics than Fe SAs@NC and Pt/C catalysts. This strategy not only offers a new way for synthesis highly efficient Fe-N/C catalysts toward ORR, but also provides the new insights into the understanding of the mechanism of adjacent Fe NPs encapsulated by nitrogen-doped carbon to Fe SAs sites.
Purpose
Even with the evidence that participation in home-sharing is highly ecologically sustainable, the existing consumer communication studies in the hospitality sector have predominantly focussed ...on the social and economic benefits. This study aims to examine how the environmental sustainability benefits of home-sharing services can be effectively communicated to consumers.
Design/methodology/approach
Two scenario-based experiments (Study 1: n = 377 and Study 2: n = 290) examined the effects of consumers’ consumption orientations, and the appeal of environmental sustainability benefits emphasised advertising on their home-sharing adoption intentions.
Findings
Study 1 demonstrated that when consumers with either a hedonic or utilitarian consumption orientation book travel accommodation, their home-sharing adoption intentions increase depending on whether advertisements are designed as hard- or soft-sell appeal, respectively. Study 2 showed that the influence of an environmental sustainability benefits emphasised advertisement that has considered consumers’ consumption orientation and applied the corresponding advertising appeal design is as effective as a home-sharing service that offers economic benefits and is even better than an advertisement that emphasises social benefits, particularly for utilitarian-oriented consumers.
Originality/value
This study is the first in the lodging sector examining the ways in which the environmental sustainability benefits of home-sharing services can be effectively communicated to consumers. The findings shed light on corporate practices pertaining to information that home-sharing service marketers can control and provide an essential basis for further advertising, consumer differences, environmental sustainability awareness and collaborative consumption studies.
Here, copper single atoms anchored on nitrogen-doped porous carbon (Cu-N/PC) derived from zeolitic imidazolate frameworks (ZIFs) as a highly efficient electrocatalyst for the oxygen reduction ...reaction (ORR) were demonstrated. Specifically, as a nitrogen-rich bridge molecule, tubular g-C3N4 (TCN) can trap free Cu ions through the electrostatic interaction in the initial stage. Then, Cu-ion-doped TCN can be used to regulate the content of copper and nitrogen doping, the electronic structure, as well as the specific surface area and pore diameter of Cu-N/PC. As a result, the high density of exposed Cu-N4 active sites and the high level of porosity in Cu-N/PC may significantly enhance the ORR activity with a more positive onset potential (E 0 = 0.97 V versus reversible hydrogen electrode (RHE)) and half-wave potential (E 1/2 = 0.88 V) than the commercially available Pt/C catalyst (E 0 = 0.94 V, E 1/2 = 0.85 V). Furthermore, the homemade Zn–air battery (ZAB) equipped with Cu-N/PC is able to deliver excellent performance, including a peak power density of 215.8 mW cm–2 and a specific capacity of 704.9 mAh g–1 based on Zn anode, outperforming the Pt/C catalyst. The finding highlights a new guideline for constructing Cu-N/PC catalyst with a well-designed structure and superior property for advanced fuel cell cathode materials.
We report a unique case of a ruptured iliac artery pseudoaneurysm caused by asymptomatic gastrointestinal perforation and retroperitoneal abscess formation. A 46-year-old man presented to the ...Emergency Department of our institution. Angiography showed a ruptured iliac artery pseudoaneurysm caused by retroperitoneal abscess formation. After endovascular repair and surgical drainage, the cause of the abscess was finally identified as a toothpick. Findings from this case show that asymptomatic gastrointestinal foreign body perforation can be a rare, but insidious, cause of an infected pseudoaneurysm. Prompt surgical intervention is sometimes necessary when treating patients with arterial pseudoaneurysm caused by a perivascular abscess.
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