[Duodenitis Russell bodies. Review of the entity and associations beyond H. pylori]. / Duodenitis con cuerpos de Russell. Revisión de la entidad y posibles asociaciones más allá del H. pylori.

Plasma cells known as "Mott cells" present non-secretable accumulations of immunoglobulins called "Russell bodies". Its presence is related to hematological neoplasms, but it can appear in chronic inflammatory processes. The most common occurrence within the digestive tract is the gastric antrum associated with H. pylori infection. Our patient is added the rare extragastric cases where the association with H. pylori is inconsistent. We have found a frequent appearance of lower digestive and urological neoplasms in relation to these cases, justified by the expression of circulating cytokines in the tumor area that lead to the overactivation of plasma cells. This possible association could lead us to know data about the tumor environment and serve us for early diagnosis or future therapeutic targets.

Construction and enhancement of built-in electric field for efficient oxygen evolution reaction.

The construction and regulation of built-in electric field (BIEF) are considered effective strategies for enhancing the oxygen evolution reaction (OER) performance of transition metal-based electrocatalysts. Herein, we present a strategy to regulate the electronic structure of nickel-iron layered double hydroxide (NiFe-LDH) by constructing and enhancing the BIEF induced by in-situ heterojunction transformation. This concept is demonstrated through the design and synthesis of Ag2S@S/NiFe-LDH (p-n heterojunction) and Ag@S/NiFe-LDH (Mott-Schottky heterojunction). Benefiting from the larger BIEF of Mott-Schottky heterojunction, efficient electron transfer occurs at the interface between silver (Ag) and NiFe-LDH. As a result, Ag@S/NiFe-LDH exhibits excellent OER performance, requiring only a 232 mV overpotential at 1 M KOH to achieve a current density of 100 mA cm-2, with a small Tafel slope of 73 mV dec-1, as well as excellent electrocatalytic durability. Density functional theory (DFT) calculations further verified that stronger BIEF in Mott-Schottky heterojunction enhances the electron interaction at the interfaces, reduces the energy barrier for the rate-determining step (RDS), and accelerates the OER kinetics. This work provides an effective strategy for designing catalyst with larger BIEF to enhance electrocatalytic activity.

A method to accelerate computational efficiency by more than two orders of magnitude for Monte Carlo simulations of electron-solid interactions.

A method has been developed to increase computational efficiency in Monte Carlo simulations of electron transport and interactions in matter. The method serves as the computational engine for the open-source code AMCSET (Aggie Monte Carlo Simulations of Electron and Ion Transport). The key is to combine n consecutive neighboring free flying distances into groups. Within each group, both flying distance and Mott scattering angles are obtained using Monte Carlo sampling under an equal energy approximation. This reduces the number of integrations of the tabulated differential Mott scattering cross-section in scattering angle selection, i.e., from 1000 to 1 if n = 1000. The method increases efficiency by more than 100 times. At the same time, the calculation still guarantees accuracy in calculating electron trajectory, excitation/ionization energy deposition, elastic scattering energy deposition, and displacement creation. For demonstration, 10 MeV electron bombardments of pure Fe with n up to 1000 are used as examples. The method, due to the availability of tabulated scattering cross-sections, is applicable for targets of the entire elemental table up to Z = 118, and for electron energies up to 900 MeV.

Constructing Built-In Electric Fields with Semiconductor Junctions and Schottky Junctions Based on Mo-MXene/Mo-Metal Sulfides for Electromagnetic Response.

The exploration of novel multivariate heterostructures has emerged as a pivotal strategy for developing high-performance electromagnetic wave (EMW) absorption materials. However, the loss mechanism in traditional heterostructures is relatively simple, guided by empirical observations, and is not monotonous. In this work, we presented a novel semiconductor-semiconductor-metal heterostructure system, Mo-MXene/Mo-metal sulfides (metal = Sn, Fe, Mn, Co, Ni, Zn, and Cu), including semiconductor junctions and Mott-Schottky junctions. By skillfully combining these distinct functional components (Mo-MXene, MoS2, metal sulfides), we can engineer a multiple heterogeneous interface with superior absorption capabilities, broad effective absorption bandwidths, and ultrathin matching thickness. The successful establishment of semiconductor-semiconductor-metal heterostructures gives rise to a built-in electric field that intensifies electron transfer, as confirmed by density functional theory, which collaborates with multiple dielectric polarization mechanisms to substantially amplify EMW absorption. We detailed a successful synthesis of a series of Mo-MXene/Mo-metal sulfides featuring both semiconductor-semiconductor and semiconductor-metal interfaces. The achievements were most pronounced in Mo-MXene/Mo-Sn sulfide, which achieved remarkable reflection loss values of - 70.6 dB at a matching thickness of only 1.885 mm. Radar cross-section calculations indicate that these MXene/Mo-metal sulfides have tremendous potential in practical military stealth technology. This work marks a departure from conventional component design limitations and presents a novel pathway for the creation of advanced MXene-based composites with potent EMW absorption capabilities.

An Ion-Mediated Spiking Chemical Neuron based on Mott Memristor.

Artificial spiking neurons capable of interpreting ionic information into electrical spikes are critical to mimic biological signaling systems. Mott memristors are attractive for constructing artificial spiking neurons due to their simple structure, low energy consumption, and rich neural dynamics. However, challenges remain in achieving ion-mediated spiking and biohybrid-interfacing in Mott neurons. Here, a biomimetic spiking chemical neuron (SCN) utilizing an NbOx Mott memristor and oxide field-effect transistor-type chemical sensor is introduced. The SCN exhibits both excitation and inhibition spiking behaviors toward ionic concentrations akin to biological neural systems. It demonstrates spiking responses across physiological and pathological Na+ concentrations (1-200 × 10-3 m). The Na+-mediated SCN enables both frequency encoding and time-to-first-spike coding schemes, illustrating the rich neural dynamics of Mott neuron. In addition, the SCN interfaced with L929 cells facilitates real-time modulation of ion-mediated spiking under both normal and salty cellular microenvironments.

Boosting photo-thermal co-catalysis CO2 methanation by tuning interface electron transfer via Mott-Schottky heterojunction effect.

Photo-thermal co-catalytic reduction of CO2 to synthesize value-added chemicals presents a promising approach to addressing environmental issues. Nevertheless, traditional catalysts exhibit low light utilization efficiency, leading to the generation of a reduced number of electron-hole pairs and rapid recombination, thereby limiting catalytic performance enhancement. Herein, a Mott-Schottky heterojunction catalyst was developed by incorporating nitrogen-doped carbon coated TiO2 supported nickel (Ni) nanometallic particles (Ni/x-TiO2@NC). The optimal Ni/0.5-TiO2@NC sample displayed a conversion rate of 71.6 % and a methane (CH4) production rate of 65.3 mmol/(gcat·h) during photo-thermal co-catalytic CO2 methanation under full-spectrum illumination, with a CH4 selectivity exceeding 99.6 %. The catalyst demonstrates good stability as it shows no decay after two reaction cycles. The Mott-Schottky heterojunction catalysts display excellent efficiency in separating photo-generated electron-hole pairs and elevate the catalysts' temperature, thus accelerating the reaction rate. The in-situ experiments revealed that light-induced electron transfer effectively facilitates H2 dissociation and enhances surface defects, thereby promoting CO2 adsorption. This study introduces a novel approach for developing photo-thermal catalysts for CO2 reduction, aiming to enhance solar energy utilization and facilitate interface electron transfer.

Origin of Distinct Insulating Domains in the Layered Charge Density Wave Material 1T-TaS2.

Vertical charge order shapes the electronic properties in layered charge density wave (CDW) materials. Various stacking orders inevitably create nanoscale domains with distinct electronic structures inaccessible to bulk probes. Here, the stacking characteristics of bulk 1T-TaS2 are analyzed using scanning tunneling spectroscopy (STS) and density functional theory (DFT) calculations. It is observed that Mott-insulating domains undergo a transition to band-insulating domains restoring vertical dimerization of the CDWs. Furthermore, STS measurements covering a wide terrace reveal two distinct band insulating domains differentiated by band edge broadening. These DFT calculations reveal that the Mott insulating layers preferably reside on the subsurface, forming broader band edges in the neighboring band insulating layers. Ultimately, buried Mott insulating layers believed to harbor the quantum spin liquid phase are identified. These results resolve persistent issues regarding vertical charge order in 1T-TaS2, providing a new perspective for investigating emergent quantum phenomena in layered CDW materials.

Unlocking Giant Third-Order Optical Nonlinearity in (MA)2CuX4 through Introducing Jahn-Teller Distortion.

Nonlinear absorption coefficient and modulation depth stand as pivotal properties of nonlinear optical (NLO) materials, while the existing NLO materials exhibit limitations such as low nonlinear absorption coefficients and/or small modulation depths, thereby severely impeding their practical application. Here we unveil that introducing Jahn-Teller distortion in a Mott-Hubbard system, (MA)2CuX4 (MA=methylammonium; X=Cl, Br) affords the simultaneous attainment of a giant nonlinear absorption coefficient and substantial modulation depth. The optimized compound, (MA)2CuCl4, demonstrates a nonlinear absorption coefficient of (1.5±0.08)×105 cm GW-1, a modulation depth of 60 %, and a relatively low optical limiting threshold of 1.22×10-5 J cm-2. These outstanding attributes surpass those of most reported NLO materials. Our investigation reveals that a more pronounced distortion of the [CuX6]4- octahedron emerges as a crucial factor in augmenting optical nonlinearity. Mechanism study involving structural and spectral characterization along with theoretical calculations indicates a correlation between the compelling performance and the Mott-Hubbard band structure of the materials, coupled with the Jahn-Teller distortion-induced d-d transition. This study not only introduces a promising category of high-performance NLO materials but also provides novel insights into enhancing the performance of such materials.

Addressing adsorption and catalysis of lithium polysulfide via electronic distribution of molybdenum carbide host.

Heterostructure engineering is considered a crucial strategy to modulate the intrinsic charge transfer behavior of materials, enhance catalytic activity, and optimize sulfur electrochemical processes. However, parsing the role of heterogeneous interface-structure-property relationships in heterostructures is still a key scientific issue to realize the efficient catalytic conversion of polysulfides. Based on this, molybdenum carbide (Mo2C) was successfully partial reduced to molybdenum metal (Mo) via a thermal reduction at high-temperature and the typical Mo-Mo2C-based Mott-Schottky heterostructures were simultaneously constructed, which realized the modulation of the electronic structure of Mo2C and optimized the conversion process of lithium polysulfides (LPS). Compared with single molybdenum carbide, the modulated molybdenum carbide acts as an electron donor with stronger Mo-S bonding strength as well as higher polysulfide adsorption energy, faster Li2S conversion kinetics, and greatly facilitates the adsorption → catalysis process of LPS. As a result, yolk-shell Mo-Mo2C heterostructure (C@Mo-Mo2C) exhibits excellent cycling performance as a sulfur host, with a discharge specific capacity of 488.41 mAh g-1 for C@Mo-Mo2C/S at 4 C and present an excellent high-rate cyclic performance accompanied by capacity decay rate of 0.08 % per cycle after 400 cycles at 2 C. Heterostructure-acting Mo2C electron distribution modulation engineering may contributes to the understanding of the structure-interface-property interaction law in heterostructures and further enables the efficient modulation of the chemical behavior of sulfur.

Mott-Schottky Construction Boosted Plasmon Thermal and Electronic Effects on the Ag/CoV-LDH Nanohybrids for Highly-Efficient Water Oxidation.

Mott-Schottky construction and plasmon excitation represent two highly-efficient and closely-linked coping strategies to the high energy loss of oxygen evolution reaction (OER), but the combined effect has rarely been investigated. Herein, with Ag nanoparticles as electronic structure regulator and plasmon exciter, Ag/CoV-LDH@G nanohybrids (NHs) with Mott-Schottky heterojunction and notable plasmon effect are well-designed. Combining theoretical calculations with experiments, it is found that the Mott-Schottky construction modulates the Fermi level/energy band structure of CoV-LDH, which in turn leads to lowered d-band center (from -0.89 to -0.93), OER energy barrier (from 6.78 to 1.31 eV), and preeminent plasmon thermal/electronic effects. The thermal effect can offset the endothermic enthalpy change of OER, promote the deprotonation of *OOH, and accelerate electron transfer kinetics. Whereas the electronic effect can increase the density of charge carriers (from 0.70 × 1020 to 1.64 × 1020 cm-3), lower the activation energy of OER (from 30.3 to 17.7 kJ mol-1). Benefiting from these favorable factors, the Ag/CoV-LDH@G NHs show remarkable electrocatalytic performances, with an overpotential of 178 and 263 mV to afford 10 and 100 mA cm-2 for OER, respectively, and a low cell voltage of 1.42 V to drive 10 mA cm-2 for overall water splitting under near-infrared light irradiation.

Lattice Strain and Mott-Schottky Effect of the Charge-Asymmetry Pd1Fe Single-Atom Alloy Catalyst for Semi-Hydrogenation of Alkynes with High Efficiency.

The ideal interface design between the metal and substrate is crucial in determining the overall performance of the alkyne semihydrogenation reaction. Single-atom alloys (SAAs) with isolated dispersed active centers are ideal media for the study of reaction effects. Herein, a charge-asymmetry "armor" SAA (named Pd1Fe SAA@PC), which consists of a Pd1Fe alloy core and a semiconducting P-doped C (PC) shell, is rationally designed as an ideal catalyst for the selective hydrogenation of alkynes with high efficiency. Multiple spectroscopic analyses and density functional theory calculations have demonstrated that Pd1Fe SAA@PC is dual-regulated by lattice tensile and Schottky effects, which govern the selectivity and activity of hydrogenation, respectively. (1) The PC shell layer applied an external traction force causing a 1.2% tensile strain inside the Pd1Fe alloy to increase the reaction selectivity. (2) P doping into the C-shell layer realized a transition from a p-type semiconductor to an n-type semiconductor, thereby forming a unique Schottky junction for advancing alkyne semihydrogenation activity. The dual regulation of lattice strain and the Schottky effect ensures the excellent performance of Pd1Fe SAA@PC in the semihydrogenation reaction of phenylethylene, achieving a conversion rate of 99.9% and a selectivity of 98.9% at 4 min. These well-defined interface modulation strategies offer a practical approach for the rational design and performance optimization of semihydrogenation catalysts.

Investigating the physical and electrical properties of La2O3 via annealing of La(OH)3.

A simple technique was utilized to fabricate pure hexagonal La2O3 nanorods by utilizing lanthanum(III) nitrate hexahydrate (La(NO3)3·6H2O) and ammonia (NH4OH). The La2O3 nanoparticles were analyzed using XRD, TGA, Raman, SEM, FTIR, TEM, PL spectroscopy, and Mott-Schottky techniques. The XRD analysis confirmed the production of La(OH)3 nanorods under appropriate conditions, which were then successfully converted into La2O2CO3 and finally into La2O3 nanorods through annealing. The TGA analysis showed that the total weight loss was due to water evaporation and the dissolution of minimal moisture present in the environment. The FTIR analysis confirmed the presence of functional groups. The SEM analysis revealed changes in morphology. The TEM analysis to determine the particle size. The PL findings showed three emission peaks at 390, 520, and 698 nm due to interband transitions and defects in the samples. The Mott-Schottky analysis demonstrated that the flatband potential and acceptor density varied with annealing temperature, ranging from 1 to 1.2 V and 2 × 1018 to 1.4 × 1019 cm-3, respectively. Annealing at 1000 °C resulted in the lowest resistance to charge transfer (Rct).

Charge Transport in the Presence of Correlations and Disorder: Organic Conductors and Manganites.

One of the most fascinating aspects of condensed matter is its ability to conduct electricity, which is particularly pronounced in conventional metals such as copper or silver. Such behavior stems from a strong tendency of valence electrons to delocalize in a periodic potential created by ions in the crystal lattice of a given material. In many advanced materials, however, this basic delocalization process of the valence electrons competes with various processes that tend to localize these very same valence electrons, thus driving the insulating behavior. The two such most important processes are the Mott localization, driven by strong correlation effects among the valence electrons, and the Anderson localization, driven by the interaction of the valence electrons with a strong disorder potential. These two localization processes are almost exclusively considered separately from both an experimental and a theoretical standpoint. Here, we offer an overview of our long-standing research on selected organic conductors and manganites, that clearly show the presence of both these localization processes. We discuss these results within existing theories of Mott-Anderson localization and argue that such behavior could be a common feature of many advanced materials.

Memristive Explainable Artificial Intelligence Hardware.

Artificial intelligence (AI) is often considered a black box because it provides optimal answers without clear insight into its decision-making process. To address this black box problem, explainable artificial intelligence (XAI) has emerged, which provides an explanation and interpretation of its decisions, thereby promoting the trustworthiness of AI systems. Here, a memristive XAI hardware framework is presented. This framework incorporates three distinct types of memristors (Mott memristor, valence change memristor, and charge trap memristor), each responsible for performing three essential functions (perturbation, analog multiplication, and integration) required for the XAI hardware implementation. Three memristor arrays with high robustness are fabricated and the image recognition of 3 × 3 testing patterns and their explanation map generation are experimentally demonstrated. Then, a software-based extended system based on the characteristics of this hardware is built, simulating a large-scale image recognition task. The proposed system can perform the XAI operations with only 4.32% of the energy compared to conventional digital systems, enlightening its strong potential for the XAI accelerator.

Realization of Organocerium-Based Fullerene Molecular Materials Showing Mott Insulator-Type Behavior.

Electron-rich organocerium complexes (C5Me4H)3Ce and [(C5Me5)2Ce(ortho-oxa)], with redox potentials E1/2 = -0.82 V and E1/2 = -0.86 V versus Fc/Fc+, respectively, were reacted with fullerene (C60) in different stoichiometries to obtain molecular materials. Structurally characterized cocrystals: [(C5Me4H)3Ce]2·C60 (1) and [(C5Me5)2Ce(ortho-oxa)]3·C60 (2) of C60 with cerium-based, molecular rare earth precursors are reported for the first time. The extent of charge transfer in 1 and 2 was evaluated using a series of physical measurements: FT-IR, Raman, solid-state UV-vis-NIR spectroscopy, X-ray absorption near-edge structure (XANES) spectroscopy, and magnetic susceptibility measurements. The physical measurements indicate that 1 and 2 comprise the cerium(III) oxidation state, with formally neutral C60 as a cocrystal in both cases. Pressure-dependent periodic density functional theory calculations were performed to study the electronic structure of 1. Inclusion of a Hubbard-U parameter removes Ce f states from the Fermi level, opens up a band gap, and stabilizes FM/AFM magnetic solutions that are isoenergetic because of the large distances between the Ce(III) cations. The electronic structure of this strongly correlated Mott insulator-type system is reminiscent of the well-studied Ce2O3.

Atomic-Limit Mott Insulator in [4]Triangulene Frameworks.

Triangulene, one unique class of zigzag-edged triangular graphene molecules, has attracted tremendous research interest. In this work, as an ultimate phase of the Mott insulator, we present the realization of the atomic-limit Mott insulator in experimentally synthesized [4]triangulene frameworks ([4]-TGFs) from first-principles calculations. The frontier molecular orbitals of the nonmagnetic [4]triangulene consist of three coupled corner modes. After the isolated [4]triangulene is assembled into [4]-TGF, one special enantiomorphic flat band is created through the coupling of these corner modes, which is identified to be a second-order topological insulator with half-filled topological corner states at the Fermi level. Moreover, [4]-TGF prefers an antiferromagnetic ground state under Hubbard interactions, which further splits these metallic zero-energy states into an atomic-limit Mott insulator with spin-polarized corners. Since the fractional filling of topological corner states is a smoking-gun signature of higher-order topology, our results demonstrate a universal approach to explore the atomic-limit Mott insulators in higher-order topological materials.

Ag engineered NiFe-LDH/NiFe2O4 Mott-Schottky heterojunction electrocatalyst for highly efficient oxygen evolution and urea oxidation reactions.

Efficient and durable electrocatalysts with sufficient active sites and high intrinsic activity are essential for advancing energy-saving hydrogen production technology. In this study, a Mott-Schottky heterojunction electrocatalyst with Ag nanoparticles in-situ grown on NiFe layered double hydroxides (NiFe-LDH)/NiFe2O4 nanosheets (Ag@NiFe-LDH/NiFe2O4) were designed and successfully synthesized through a hydrothermal process and subsequent spontaneous redox reaction. The in-situ growth of metallic Ag on semiconducting NiFe-LDH/NiFe2O4 triggers a strong electron interaction across the Mott-Schottky interface, leading to a significant increase in both the intrinsic catalytic activity and the electrochemical active surface area of the heterojunction electrocatalyst. As a result, the Ag@NiFe-LDH/NiFe2O4 demonstrates impressive oxygen evolution reaction (OER) performance in alkaline KOH solution, achieving a low overpotential of 249 mV at 100 mA cm-2 and a Tafel slope of 42.79 mV dec-1. When the self-supported Ag@NiFe-LDH/NiFe2O4 is coupled with the Pt/C electrocatalyst, the alkaline electrolyzer reaches a current density of 10 mA cm-2 at a cell voltage of only 1.460 V. Furthermore, X-ray photoelectron spectroscopy and in-situ Raman analysis reveal that the Ni(Fe)OOH is the possible active phase for OER in the catalyst. In addition, when employed for UOR catalysis, the Ag@NiFe-LDH/NiFe2O4 also displays intriguing activity with an ultralow potential of 1.389 V at 50 mA cm-2. This work may shed light on the rational design of multiple-phase heterogeneous electrocatalysts and demonstrate the significance of interface engineering in enhancing catalytic performance.

Effective Bidirectional Mott-Schottky Catalysts Derived from Spent LiFePO4 Cathodes for Robust Lithium-Sulfur Batteries.

It is deemed as a tough yet profound project to comprehensively cope with a range of detrimental problems of lithium-sulfur batteries (LSBs), mainly pertaining to the shuttle effect of lithium polysulfides (LiPSs) and sluggish sulfur conversion. Herein, a Co2P-Fe2P@N-doped carbon (Co2P-Fe2P@NC) Mott-Schottky catalyst is introduced to enable bidirectionally stimulated sulfur conversion. This catalyst is prepared by simple carbothermal reduction of spent LiFePO4 cathode and LiCoO2. The experimental and theoretical calculation results indicate that thanks to unique surface/interface properties derived from the Mott-Schottky effect, full anchoring of LiPSs, mediated Li2S nucleation/dissolution, and bidirectionally expedited "solid⇌liquid⇌solid" kinetics can be harvested. Consequently, the S/Co2P-Fe2P@NC manifests high reversible capacity (1569.9 mAh g-1), superb rate response (808.9 mAh g-1 at 3C), and stable cycling (a low decay rate of 0.06% within 600 cycles at 3C). Moreover, desirable capacity (5.35 mAh cm-2) and cycle stability are still available under high sulfur loadings (4-5 mg cm-2) and lean electrolyte (8 µL mg-1) conditions. Furthermore, the as-proposed universal synthetic route can be extended to the preparation of other catalysts such as Mn2P-Fe2P@NC from spent LiFePO4 and MnO2. This work unlocks the potential of carbothermal reduction phosphating to synthesize bidirectional catalysts for robust LSBs.

Distribution and Clinicopathological Features of Mott Cells (Plasma Cells Containing Russell Bodies) in Gastric Cancer: Presence of Mott Cells Is Associated with Favorable Prognosis.

Gastric cancer (GC) is still one of the leading causes of cancer-related mortality. We previously reported the relationship between histological heterogeneity of tumor cells and molecular features in GC. The tumor microenvironment also has a crucial role in GC progression and therapeutic resistance. In this study, we focused on the tumor microenvironment, especially inflammatory cells in GC. Using GC tissue slides, we investigated the distribution and clinicopathological significance of inflammatory cell counts including eosinophils, neutrophils, lymphocytes, and plasma cells. Additionally, we investigated the relationship between Mott cells (plasma cells containing Russell bodies) and clinicopathological features. In neoplastic gastric mucosa, a high number of plasma cells was associated with low T-grade, early stage, and good prognosis. We then focused on Mott cells and found that their presence in neoplastic gastric mucosa was associated with lower T and N grades, early stage, and Helicobacter pylori infection and was inversely associated with CD44 and EGFR expression. Additionally, the presence of Mott cells was associated with good prognosis in advanced GC and was an independent favorable prognostic predictor. The presence of Mott cells in GC might be one useful prognostic predictor, and Mott cells might have an important role in the carcinogenesis of H. pylori infection.

Subnanometer Scale Mapping of Hydrogen Doping in Vanadium Dioxide.

Hydrogen donor doping of correlated electron systems such as vanadium dioxide (VO2) profoundly modifies the ground state properties. The electrical behavior of HxVO2 is strongly dependent on the hydrogen concentration; hence, atomic scale control of the doping process is necessary. It is however a nontrivial problem to quantitatively probe the hydrogen distribution in a solid matrix. As hydrogen transfers its sole electron to the material, the ionization mechanism is suppressed. In this study, a methodology mapping the doping distribution at subnanometer length scale is demonstrated across a HxVO2 thin film focusing on the oxygen-hydrogen bonds using electron energy loss spectroscopy (EELS) coupled with first-principles EELS calculations. The hydrogen distribution was revealed to be nonuniform along the growth direction and between different VO2 grains, calling for intricate hydrogenation mechanisms. Our study points to a powerful approach to quantitatively map dopant distribution in quantum materials relevant to energy and information sciences.