Facet Junction Research Articles

Microsurgical and Descriptive Three-Dimensional Analysis of the Subarticular Trigone: A Guidemap for Standardizing Lateral Recess Decompression.

Background Lateral recess decompression has remained a cornerstone spinal procedure for decades. Despite its popularity, a significant lack of evidence in the literature exists concerning microsurgical anatomy and pertinent surgical landmarks, resulting in non-standardized nomenclature, descriptions, and surgical approaches. Objective This study provides an in-depth microsurgical and descriptive analysis of the subarticular trigone (SAT), serving as an anatomical guide and a tool to foster consistency in nomenclature and standardization of surgical approaches. Methods We analyzed 35 high-resolution lumbar spine CT scans, employing three-dimensional (3D) processing techniques. The SAT is introduced to delineate the bony prominence enveloping the superiomedial quadrant of the pedicle. The SAT encompasses two zones: (1) a superior zone above the superior pedicular line, corresponding to the medial part of the body of the ascending facet (AF), and (2) an inferior zone between the superior and middle pedicular lines, corresponding to the root of the AF and the medial pars/superior lamina. The superior subarticular point (SSP) and medial subarticular point (MESP) serve as key reference landmarks. The SAT forms the roof of the lateral recess and the region requiring resection during decompression of the traversing root in this anatomical corridor. Various measurements, including SSP and MESP to lateral pars, tip of the facet and spino-laminar junction distance, mean width of the sublaminar ridge (SLR), and percentage of the facet that requires resection for adequate SAT decompression, were carried out. Results The mean distance of the SSP to the lateral pars ranges from 7 to 9.2 mm, to the tip of the descending from 9.3 to 10.1 mm, and to the spino-laminar junction from 6.7 to 8.1 mm. The MESP is located at a mean distance of 5.4-6.9 mm from the medial pedicular line. The mean width of the SLR varies from 18.6 to 29.4 mm. Finally, the percentage of total facet width that needs to be removed to adequately decompress the SAT extends from 32% at L4 to 36% at L1. Conclusions This study presents comprehensive insights into the surgical, descriptive, and correlative anatomy of the lateral recess, emphasizing the SAT. The extrapolated data offer a framework for achieving uniformity in surgical planning and advocate for standardized nomenclature.

Tandem Electric-Fields Prolong Energetic Hot Electrons Lifetime for Ultra-Fast and Stable NO2 Detection.

Prolonging energetic hot electrons lifetimes and surface activity in the reactive site can overcome the slow kinetics and unfavorable thermodynamics of photo-activated gas sensors. However, bulk and surface recombination limit the simultaneous optimization of both kinetics and thermodynamics. Here tandem electric fields are deployed at (111)/(100)Au-CeO2 to ensure a sufficient driving force for carrier transfer and elucidate the mechanism of the relationship between charge transport and gas-sensing performance. The asymmetric structure of the (111)/(100)CeO2 facet junction provides interior electric fields, which facilitates electron transfer from the (100)face to the (111)face. This separation of reduction and oxidation reaction sites across different crystal faces helps inhibit surface recombination. The increased electron concentration at the (111)face intensifies the interface electric field, which promotes electron transfer to the Au site. The local electric field generated by the surface plasmon resonance effect promotes the generation of high-energy energy hot-electrons, which maintains charge concentration in the interface field by injecting into (111)/(100)CeO2, thereby provide thermodynamic contributions and inhibit bulk recombination. The tandem electric fields enable the (111)/(100)Au-CeO2 to rapidly detect 5ppm of NO2 at room temperature with stability maintained within 20s.

Constructing the facet junction on solid solution BiOBr1-xClx for efficient photocatalytic CO2 reduction with H2O

Photocatalytic conversion of CO2 to renewable clean fuels was a promising way to alleviate the energy crisis and solve environmental issues. However, it remained significantly challenging for designing highly efficient photocatalysts. Herein, the solid solution BiOBr1-xClx (0 ≤ x ≤ 1, BOBC-n, n represented the amount of molten salt) with (001)/(102) facet junction was constructed through a molten salt method. In situ photochemical probing demonstrated that distinct exposed facets allowed photogenerated holes and electrons to migrate to the dominantly exposed and co-exposed facets and thus exhibited different reactivity. Benefiting from facet junction, the optimized BOBC-0.5 exhibited the superior performance of photocatalytic CO2 to CH3OH (5.52 μmol·g−1·h−1) to that of BiOBr with (001)/(110) facet junction (1.78 μmol·g−1·h−1). The density functional theory (DFT) calculations further confirmed the separation path of photogenerated carriers between distinct facets, which realized the effective spatial separation of electrons and holes. Moreover, the (102) facet revealed superior adsorption energy of CO2 molecules to that of (110) facet. This work highlighted a molten-salt strategy to build facet junction for boosting photocatalytic CO2 performance.

Facet junction engineering for enhanced SERS activity of Ag/Cu2O composite substrates.

Featuring ultra-high sensitivity and molecule-specific detection ability, surface-enhanced Raman scattering (SERS) is suitable for the rapid sensing of trace-level chemicals in biological, environmental, and agricultural samples. Although crystal facet junction engineering is a powerful tool to manipulate the optoelectronic properties of semiconducting materials, its correlation with the SERS sensing activity of noble metal/semiconductor composites has still not been clarified. In this work, Ag was deposited on Cu2O nanocrystals enclosed by different facets, including {100} (cube), {111} (octahedron), and {100}/{111} (truncated octahedron), and a detailed study of their SERS performance was carried out. It was found that Ag/truncated-octahedral Cu2O (Ag/Cu2O(J3)) exhibited superior SERS activity to Ag/cubic Cu2O (Ag/Cu2O(C)) and Ag/octahedral Cu2O (Ag/Cu2O(O)). The {100}/{111} facet junction in Cu2O can promote the separation and transfer of photogenerated charge carriers, which is beneficial for enhancing SERS sensing performance. Moreover, Ag/Cu2O(J3) has a higher content of oxygen vacancies, providing extra interfacial charge-transfer pathways to the analyte, which also contribute to improving the SERS activity. The low detection limit of Ag/Cu2O(J3) was 1 × 10-11 M for 4-nitrobenzenethiol, two orders of magnitude lower than that of Ag/Cu2O(C) and Ag/Cu2O(O). In addition, Ag/Cu2O(J3) could detect CV and R6G at concentrations down to 1 × 10-10 M and 1 × 10-8 M, respectively. The findings of this work can provide insightful information for designing metal/semiconductor substrates toward SERS sensing application by regulating the crystal facet junction.

Ferroelectric Polarization Modulated Facet-selective Charge Separation in Bi4 NbO8 Cl Single Crystal for Boosting Visible-light Driven Bifunctional Water Splitting.

Developing bifunctional water-splitting photocatalysts is meaningful, but challenged by the harsh requirements of specific-facet single crystals with spatially separated reactive sites and anisotropic charge transfer paths contributed by well-built charge driving force. Herein, tunable ferroelectric polarization is introduced in Bi4 NbO8 Cl single crystal nanosheets to strengthen the orthogonal charge transfer channels. By manipulating the in-plane polarization from octahedral off-centering of Nb5+ and out-of-plane polarization from lone pair electron effect of anisotropic Bi3+ , both the fast charge recombination in bulk catalyst and the process of charge trapping into surface states can be effectively modulated. Collaborating with modest polarization electric field and facet junction induced built-in electric field, cooperative charge tractive force is constructed, which reinforces the spatial separation and migration of photogenerated electrons and holes to {110} reductive site facet and {001} oxidation site facet, respectively. While excessive polarization charges impair the facet-selective charge separation characteristics and conversely promote charge recombination on the surface. As a result, polarity-optimized Bi4 NbO8 Cl shows an excellent H2 and O2 evolution rate of 54.21 and 36.08 μmol ⋅ h-1 in the presence of sacrificial reagents under visible light irradiation. This work unveils the function of ferroelectric polarization in tuning the intrinsic facet-selective charge transfer process of photocatalysts.

Ferroelectric Polarization Modulated Facet‐selective Charge Separation in Bi4NbO8Cl Single Crystal for Boosting Visible‐light Driven Bifunctional Water Splitting

AbstractDeveloping bifunctional water‐splitting photocatalysts is meaningful, but challenged by the harsh requirements of specific‐facet single crystals with spatially separated reactive sites and anisotropic charge transfer paths contributed by well‐built charge driving force. Herein, tunable ferroelectric polarization is introduced in Bi4NbO8Cl single crystal nanosheets to strengthen the orthogonal charge transfer channels. By manipulating the in‐plane polarization from octahedral off‐centering of Nb5+ and out‐of‐plane polarization from lone pair electron effect of anisotropic Bi3+, both the fast charge recombination in bulk catalyst and the process of charge trapping into surface states can be effectively modulated. Collaborating with modest polarization electric field and facet junction induced built‐in electric field, cooperative charge tractive force is constructed, which reinforces the spatial separation and migration of photogenerated electrons and holes to {110} reductive site facet and {001} oxidation site facet, respectively. While excessive polarization charges impair the facet‐selective charge separation characteristics and conversely promote charge recombination on the surface. As a result, polarity‐optimized Bi4NbO8Cl shows an excellent H2 and O2 evolution rate of 54.21 and 36.08 μmol ⋅ h−1 in the presence of sacrificial reagents under visible light irradiation. This work unveils the function of ferroelectric polarization in tuning the intrinsic facet‐selective charge transfer process of photocatalysts.

“X-Scheme” Charge Separation Induced by Asymmetrical Localized Electronic Band Structures at the Ceria Oxide Facet Junction

“X-Scheme” Charge Separation Induced by Asymmetrical Localized Electronic Band Structures at the Ceria Oxide Facet Junction

Acid-inducing {110}/{121} facet junction formation boosting the selectivity and activity of CO2 photoreduction by BaTiO3 nanoparticles

With the introduction of {110} facets and an increasing exposure ratio, the photoreduction CO2 reaction of acid-etched BaTiO3 occurs on different facets of BaTiO3, and the corresponding reactants/products and photocatalytic mechanism are presented.

Self-Doping Based Facet Junctions and Oxygen Vacancies in Ferroelectric Bi3TixNb2-xO9 Nanosheets for Boosting Photocatalytic Degradation and Antibacterial Activity.

Constructing facet junction in semiconductor photocatalysts has been demonstrated as an effective method to promote charge-carrier separation and suppress carrier recombination. Herein, we proposed a novel but facile self-doping strategy to regulate the crystal facet exposure ratio in ferroelectric Bi3TixNb2-xO9 single-crystalline nanosheets, thereby optimizing its facet junction effect. Through tuning the atomic ratio of Ti and Nb, the exposure ratio of {001} and {110} crystal planes in Bi3TixNb2-xO9 nanosheets can be delicately modulated, and more {110} facets were exposed with the increase of the Ti/Nb atomic ratio as evidenced by the X-ray diffraction and scanning electron microscopy results. A facet junction between {110} and {001} crystal planes was verified based on the density functional theory calculation and photodeposition experiment results. Photogenerated electrons tend to accumulate in {110}, while holes gathered in {001} crystal planes. Owing to the optimal facet junction effect, the sample of Ti1.05 shows the most efficient charge-carrier separation and transportation compared to Ti0.95 and Ti1.00 as supported by the photoluminescence, surface photovoltage, photoelectrochemistry, and electron paramagnetic resonance (EPR) results. In addition, the oxygen vacancy arising from the inequivalent substitution of Nb5+ by Ti4+ as proved by X-ray photoelectron spectroscopy and EPR results and the enhanced ferroelectricity supported by P-E loops can also assist charge-carrier separation and migration. Benefiting from these properties, Ti1.05 outperformed Ti0.95 and Ti1.00 in the photodegradation of organic dye and antibiotic molecules. Meanwhile, the excellent antibacterial activity of Ti1.05 under visible light was also demonstrated by the Escherichia coli sterilization experiment. This work not only presents a novel pathway to adjust the facet junction but also provides new deep insights into the crystal facet engineering in ferroelectrics as photocatalysts.

Facet junction of CeO2 with high SERS activity for sensitive detection of ATP

Crystal facet engineering is proven to improve charge transfer of semiconductors. However, the facet-dependent properties and potential mechanisms of CeO2 for surface-enhanced Raman scattering (SERS) performance have not been explored. SERS effect is a surface sensitive technology, so it is very important to study the relationship between semiconductor surface topography and SERS activity. Here, we synthesized CeO2 (J2) with co-exposed {100} and {111} facet junction to effectively promote charge transfer (CT) between CeO2 (J2) substrate and methylene blue (MB), so that the SERS activity is significantly enhanced compared to CeO2 with only one exposed facets, which had a higher SERS activity with an enhancement factor (EF) of 3.77 × 106. The phenomenon is due to that the facet junction of CeO2 (J2) can promote electron-hole (e--h+) separation under light irradiation for more efficient CT. In addition, the oxygen vacancies enriched in CeO2 (J2) can provide an extra charge transfer path, which also facilitates the enhancement of SERS activity. Furthermore, the CeO2 (J2) with excellent SERS activity was used to detect ATP with a detection limit of 6.90 nM. This work provides a new SERS platform and opens up a perspective for preparation of SERS semiconductor substrates.

Insight into symmetry matching heterogeneous facet junction photocatalysts via {211} faceted CeO2 nanobelts@δ-Bi2O3 nanowires

Photocatalysts with homogenous facet junctions exhibit amazing performance in photocatalytic redox reactions. More challenging and alluring is the construction of heterogeneous facet junctions with two of them. Herein, we show a self-assembly procedure to buildup co-exposing faceted δ-Bi2O3 nanowires on the edges of co-exposing {211} faceted CeO2 nanobelts from sub 10 nm nanoparticles. Directed by surface O-vacancy energy, the δ-Bi2O3 nanoparticles preferentially adsorbed on the {111} facets of CeO2 nanobelts and oriented growth into co-exposing faceted δ-Bi2O3 nanowires. The CeO2@δ-Bi2O3 hetero facet junction displays superior and stable hydrogen evolution activities, 5.2 times of the pure co-exposing faceted CeO2 nanobelts, ascribed to following key factors: First, heterogeneous facet junctions contribute to efficient interplanar and inter-junction separation of photocarriers. Moreover, symmetry matching leads to strong connection between the two facet junctions, facilitating the dynamic charge transfer. This work can provide a new strategy in the design of heterojunction photocatalytic systems for water splitting.

Graphene triggered hole activation strategy for 2D/2D-Layered (0 0 1)/(1 0 0)WO3 facet junction towards enhanced photocatalytic water oxidation kinetics

An unique graphene hybridized 2D ternary GR/(001)/(100)WO3 facet junction is designed by combining the advantages of heterojunction and unique bi-functional graphene working as hole trap and co-catalyst in photocatalytic water splitting. By a facile two-step hydrothermal method, (001)WO3 with highly exposed facet is connected to graphene through -C-W-“bridge”, while (100)WO3 grows on the surface of (001)WO3 affording efficient generation of photocharges. GR/(001)/(100)WO3 is highly active in oxidation of water, with an apparent quantum efficiency of 26.7 % at 420 nm. The -C-W- “bridge” acts as electron transfer channel for construction of internal electric field at GR/(001)WO3 interface, which would direct photo-generated holes towards graphene for water oxidation. The charges dynamics analysis and theoretical simulations demonstrate that the superior photocatalytic activity mainly results from the synergistic promoting effects of the improved separation and prolonged lifetime of photocharges, the reduced energy barrier for OO formation, and the lower overpotential of water oxidation reaction comparable to the most efficient RuO2. This work provides a promising pathway to develop graphene hybridizing structure with dual functions for boosting photocatalytic reactions.

Facet synergy dominant Z-scheme transition in BiOCl with enhanced 1O2 generation

BiOCl powders with different morphology were obtained through self-assembling. Their photocatalytic performance was tested through degradation of organic dye and mechanism of photocatalytic for obtained samples were investigated. Relevant characterization demonstrated that facet synergy was a main reason of photocatalytic performance promotion due to changed facet exposure and proportion under self-assembling. Theory and experimental analysis manifested that synergistic facet stimulated Z scheme transition in samples with lower (001) facet proportion, which provided favorable condition of 1O2 generation and simultaneously generated prominent charge separation. This work unveiled the facet synergy dominant photocatalytic performance improvement in self-assembling system of BiOCl and verified decisive role of facet proportion in constructing Z-scheme facet junction, which also prompted possibility of improving 1O2 generation through facet engineering under self-assembling.

Semiconductor facet junctions for photocatalytic CO2 reduction

Abstract Photocatalytic carbon dioxide (CO2) conversion has been recognized as one of the promising strategies for unraveling current environmental and energy problems attributed to the growing fossil fuel consumption of the human society because it can directly harness incident sunlight energy for converting waste CO2 into valuable compounds. Increasing attention has been provoked to the semiconductor facet junction photocatalysts due to their unique feature in enhancing the photogenerated electron–hole pair utilization toward improving the photocatalytic CO2 conversion performance. In the past decade, significant breakthroughs in the semiconductor facet junction photocatalysts for photocatalytic CO2 conversion. In this review, we give a brief introduction on the development and the idea of the semiconductor facet junction photocatalysts. Then, the unique advantages of the semiconductor facet junction photocatalysts for photocatalytic CO2 conversion are summarized. Subsequently, the recent development of semiconductor facet junction photocatalysts in photocatalytic CO2 conversion is overviewed. We end this review by presenting the perspectives and challenges in this field for its future advancement toward practical applications. This review is expected to push forward the development of not only photocatalytic CO2 conversion but also other energy and environmental photocatalytic applications.

Irradiation-induced grain boundary facet motion: In situ observations and atomic-scale mechanisms.

Metals subjected to irradiation environments undergo microstructural evolution and concomitant degradation, yet the nanoscale mechanisms for such evolution remain elusive. Here, we combine in situ heavy ion irradiation, atomic resolution microscopy, and atomistic simulation to elucidate how radiation damage and interfacial defects interplay to control grain boundary (GB) motion. While classical notions of boundary evolution under irradiation rest on simple ideas of curvature-driven motion, the reality is far more complex. Focusing on an ion-irradiated Pt Σ3 GB, we show how this boundary evolves by the motion of 120° facet junctions separating nanoscale {112} facets. Our analysis considers the short- and mid-range ion interactions, which roughen the facets and induce local motion, and longer-range interactions associated with interfacial disconnections, which accommodate the intergranular misorientation. We suggest how climb of these disconnections could drive coordinated facet junction motion. These findings emphasize that both local and longer-range, collective interactions are important to understanding irradiation-induced interfacial evolution.

Coupling Long-Range Facet Junction and Interfacial Heterojunction via Edge-Selective Deposition for High-Performance Z-Scheme Photocatalyst.

The construction of photocatalytic systems that have strong redox capability, effective charge separation, and large reactive surfaces is of great scientific and practical interest. Herein, an edge‐connected 2D/2D Z‐scheme system that combines the facet junction and the interfacial heterojunction to achieve effective long‐range charge separation and large reactive surface exposure is designed and fabricated. The heterostructure is realized by the selective growth of 2D‐layered MoS2 nanoflakes on the edge‐sites of thin TiO2 nanosheets via an Au‐promoted photodeposition method. Attributed to the synergetic coupling of the facet junction and the interfacial heterojunction that assures the effective charge separation, and the tremendous but physically separated reactive sites offered by layered MoS2 and highly‐exposed (001) facets of TiO2, respectively, the artificial Z‐scheme exhibits excellent photocatalytic performance in photodegradation tests. Moreover, the junctional plasmonic Au nanoclusters not only act as electron traps to promote the edge‐selective synthesis but also generate “hot electrons” to further boost photocatalytic performance. The Z‐scheme charge‐flow direction in the heterostructure and the roles of electrons and holes are comprehensively studied using in situ irradiated X‐ray photoelectron spectroscopy and photodegradation tests. This work offers a new insight into designing high‐performance Z‐scheme photocatalytic systems.

Mechanism Insight into an Unprecedented Dual Series‐Parallel Photocharge Separation in Quaternary Cu2O Facet Junctions

AbstractUncovering the contribution of anisotropic crystal facets in single‐crystalline photocatalysts is still a challenge in fundamental study. Here, the mechanism underlying facet junction‐dependent photocharge separation in polyhedral Cu2O is demonstrated, which is beneficial for understanding why 50‐faceted Cu2O exhibiting quaternary {100}/{110}/{111}/{522} facet junction possesses an enhanced photodegradation activity toward tetracycline than that of the 26‐faceted Cu2O exhibiting ternary {100}/{110}/{111} and 18‐faceted Cu2O exhibiting binary {100}/{110} facet junction. Density functional theory (DFT) calculations and selective photodeposition results confirm that hierarchical facet junctions are formed in a 50‐faceted Cu2O, which could be regarded as one parallel connection between binary {110}/{111} and ternary {110}/{522}/{100} series facet junction for conduction band minimum, and another parallel connection between binary {100}/{522} and ternary {111}/{110}/{522} series facet junction for valence band maximum, leading to an unprecedented dual series‐parallel transfer pathway for more efficiently improved photocharge separation. Hopefully, this study would be a beneficial guideline for scientific researchers currently concentrating on the facet junction engineering of polyhedral photocatalysts.

Graphene Triggered Hole Activation Strategy for 2d/2d-Layered (001)/(100)Wo3 Facet Junction Towards Enhanced Photocatalytic Water Oxidation Kinetics

Graphene Triggered Hole Activation Strategy for 2d/2d-Layered (001)/(100)Wo3 Facet Junction Towards Enhanced Photocatalytic Water Oxidation Kinetics

Facet junction of BiOBr nanosheets boosting spatial charge separation for CO2 photoreduction

Understanding on the photogenerated charge separation from a microscopic level remains a challenge and is highly desirable as it provides a cornerstone for designing high-performance photocatalysts. Herein, facet engineering is chosen as a tool to reveal the relationship between the charge separation/transfer and crystal structure. A series of BiOBr nanosheets with dominantly exposed facet of (001) or (010) as well as different lateral facet exposure ratios are constructed via adjusting pH value during the hydrothermal process. It is found that exposure of anisotropic crystal facets allows the separative transfer of photogenerated electrons and holes onto the lateral facets and dominantly exposed facets, respectively, which is attributed to the junction formed between distinct facets (i.e., facet junction). In the case of BiOBr-5 with (010)/(102) facet junction, the electron transfer rate (kET) and efficiency (ηET) are 3.658 × 106s−1 and 54.09%, which are superior than the counterpart of BiOBr-1 with (001)/(110) facet junction. The fast electron transfer rate and high transfer efficiency of BiOBr-5 result in the high CO evolution rate from CO2 photoreduction under artificial sunlight. Our work may bring some new insights into the mechanism of facet junction and rational design of photocatalysts with high performance for solar energy storage in future.

Facet Junction Engineering for Photocatalysis: A Comprehensive Review on Elementary Knowledge, Facet‐Synergistic Mechanisms, Functional Modifications, and Future Perspectives

AbstractA facet junction (also called facet heterojunction or surface heterojunction) is defined as a complex polyhedral single crystal exposed to two, three, or four types of crystallographic planes, and is a promising platform for achieving multifunctional photocatalysis. Compared with simple polyhedral counterparts enclosed by the same crystallographic planes or conventional heterogeneous junctions, facet junctions have notable facet‐crosslinking effects arising from different electronic structures of heterogeneous facets, which is beneficial for promoting the transfer and separation of photogenerated charge carriers in a single‐crystalline semiconductor without the introduction of external species or interfaces. However, there are few specialized review articles on facet junction engineering of photocatalysts. Herein, an overview of facet junction‐based photocatalysts is provided based on the following aspects: elementary knowledge, microstructural features, intrinsic facet‐synergistic mechanisms, functional modifications, enhanced photocatalytic mechanisms, challenges and issues, and directions for future investigations. This review article will act as a theoretical base for researchers who are focused on facet‐dependent effects to design and fabricate new photocatalysts.