Yolk-shell Nanostructures Research Articles

Enhanced Ferroelectric Polarization in Au@BaTiO3 Yolk-in-Shell Nanostructure for Synergistic Boosting Visible-Light- Piezocatalytic CO2 Reduction.

Developing efficient photo-piezocatalytic systems to achieve the conversion of renewable energy to chemical energy emerges enormous potential. However, poor catalytic efficiency remains a significant obstacle to future practical applications. Herein, a series of unique Au@BaTiO3 (Au@BT) yolk-shell nanostructure photo-piezocatalyst is constructed with single Au nanoparticle (Au NP) embedded in different positions within ferroelectric BaTiO3 hollow nanosphere (BT-HNS). This special structure showcases excellent mechanical force sensitivity and provides ample plasmon-induced interfacial charge-transfer pathways. In addition, the powerful piezoelectric polarization electric field induced by the enhanced ferroelectric polarization electric field via corona poling treatment in BT-HNS further promotes charge separation, CO2 adsorption and key intermediate conversion. Notably, BT with single Au NP encapsulated into hollow nanosphere shell with reinforced polarization (Au@BT-1-P) shows synergistically improved photo-piezocatalytic CO2 reduction activity for producing CO with a high production rate of 31.29 µmol g-1 h-1 under visible light irradiation and ultrasonic vibration. This work highlights a generic tactic for optimized design of high-performance and multifunctional nanostructured photo-piezocatalyst. Meanwhile, these yolk-in-shell nanostructures with single Au nanoparticle as an ideal model may hold great promise to inspire in-depth exploration of carrier dynamics and mechanistic understanding of the catalytic reaction.

Yolk-Shell Au NPs@Carbon Porous Nanoreactors Derived from ZIF-8: A High-Efficiency Catalyst for Three-Component Coupling Reaction.

A yolk-shell Au NPs@carbon porous nanoreactor with an active gold (Au) core and a porous carbon shell has been fabricated and demonstrates excellent high activity and cyclic stability as a heterogeneous catalyst for the three-component coupling reaction of aldehyde, amine, and alkyne. Remarkably, the unique yolk-shell nanostructure can protect gold nanoparticles (Au NPs) from aggregation, allow for efficient mass transport, and benefit substrate enrichment, giving rise to enhanced activity, stability, and recyclability.

High-performance assaying cardiac troponin I using Bi-doped tin-based heterojunction in photoelectrochemical biosensing with the quencher of yolk-shell nanostructure

Cardiac troponin I (cTnI), a protein regulating myocardial contraction, stands the premier biomarker for diagnosing acute myocardial infarction and stratifying heart disease risk. Photoelectrochemical (PEC) biosensing combines traditional PEC analysis with high bioconjugation specificity, rendering a prospective avenue for disease biomarker analysis. However, the performance of sensors often falls short due to inadequate photoelectric materials. Hence, designing heterojunctions with proper band alignment, effective transport and separation of photogenerated carriers is highly expected for PEC sensors. Meanwhile, doping as a synergistic strategy to tune the energy band edges and improve carrier transport in heterojunctions, can also enhance the sensing performance. In this work, bismuth-doped tin oxide and tin disulfide heterojunction (Bi–SnOS) was prepared via a simple one-step hydrothermal method and utilized as a highly sensitive platform. Integrating copper sulfide-coated nano-gold (Au@CuS), a yolk-shell shaped nanocomposites, as the double quenching probe, an excellent PEC biosensor was fabricated to assay cTnI via sandwich immunorecognition. Under optimal conditions, the proposed biosensor displayed a high-performance for cTnI in the range from 0.1 pg/mL to 5.0 ng/mL with a low detection limit (44.7 fg/mL, 3σ). The strong photocurrent response, high stability and suitable selectivity point out that the synergistic effect between heterojunction and doping provides a promising prospect for the design of new PEC materials.

Yolk-shell electron-rich Ru@hollow pyridinic-N-doped carbon nanospheres with tunable shell thickness and ultrahigh surface area for biomass-derived levulinic acid hydrogenation under mild conditions

Aiming to efficiently upgrade renewable biomass-derived levulinic acid (LA) into γ-valerolactone (GVL), we have devised yolk-shell electron-rich Ru@hollow pyridinic-N-doped carbon nanospheres, featuring a tunable shell thickness (20−70 nm) and an ultrahigh surface area (4016 m2 g−1). Experimental and theoretical investigations reveal that the strategic formation of the yolk-shell structure and appropriate thinning of the carbon shell facilitate the generation of electron-rich Ru0 and a positive shift of the d-band center towards the Fermi level by increasing surface pyridinic-N species. These modifications suitably intensify Ru0−H interaction, promote reactant adsorption, stimulate electron transfer between active H and the CO group of LA, and ultimately reduce apparent activation energy. Consequently, a high LA turnover frequency (18733.4 h−1 at 30 °C) and GVL selectivity (99.9%), alongside excellent stability up to eight cycles, are achieved, markedly outperforming externally-supported analogues. These findings afford valuable insights into designing yolk-shell nanostructures for biomass upgrading through microenvironment engineering.

MOF-derived yolk-shell CoN/Co-NC@SiO2 nanozyme with oxidase mimetic activities for colorimetric detection of glutathione

The development of nanozymes has garnered significant attention in biosensing applications owing to their exceptional catalytic properties and structural tunability. Herein, we present a yolk-shell nanozyme derived from metal-organic frameworks (MOFs) featuring CoN/Co-NC@SiO2 architecture, exhibiting remarkable oxidase mimetic activities for colorimetric glutathione (GSH) detection. The synthesis involves a facile pyrolysis process of cobalt-based MOFs encapsulated within a silica shell, resulting in a unique yolk-shell nanostructure with CoN/Co-NC active sites. Yolk-shell CoN/Co-NC@SiO2 has been studied in detail as an oxidase and catalase-like nanozyme. In consideration of structural and composition modulation, including hydrophilic SiO2 shell, the unique cavity, a high specific surface area and dispersed active sites, the CoN/Co-NC@SiO2 was proposed for colorimetric detection of glutathione with its oxidase-like activities. Based on the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) by CoN/Co-NC@SiO2, a wide linear detection range of 0.5–60 μM as well as a lower detection limit of 0.054 μM were obtained. Our research shows that optimizing structure and composition plays an important role in the construction of multiple-enzyme activity and offers bright potential applications of MOF-derived yolk-shell nanozymes in biosensing and medical diagnostics.

ZIFs-Derived Hollow Nanostructures via a Strong/Weak Coetching Strategy for Long-Life Rechargeable Zn-Air Batteries.

Recently, zeolitic imidazolate frameworks (ZIFs) composites have emerged as promising precursors for synthesizing hollow-structured N-doped carbon-based noble-metal materials with diverse structures and compositions. Here, a strong/weak competitive coordination strategy is presented for synthesizing high-performance electrocatalysts with hollow features. During the competitive coordination process, the cubic zeolitic-imidazole framework-8 (Cube-8)@ZIF-67 with core-shell structures are transformed into Cube-8@ZIF-67@PF/POM with yolk-shell nanostructures employing phosphomolybdic acid (POM) and potassium ferricyanide (PF) as the strong chelator and the weak chelator, respectively. After calcination, the hollow Mo/Fe/Co@NC catalyst exhibits superior performance in both oxygen evolution reaction (OER) and oxygen reduction reaction (ORR). Interestingly, the Mo/Fe/Co@NC catalyst exhibits efficient electrocatalytic performance for Zn-air batteries (ZABs), with a high power density (≈150mW cm-2) and superior cycling life (≈500h) compared to commercial platinum/carbon (Pt/C) and ruthenium dioxide (RuO2) mixture benchmarks catalysts. In addition, the density functional theory further proves that after the introduction of Mo and Fe atoms, the adsorption energy with the adsorption intermediates is weakened by adjusting the d-band center, thus weakening the reaction barrier and promoting the reaction kinetics of OER. Undoubtedly, this study presents novel insights into the fabrication of ZIFs-derived hollow structure bifunctional oxygen electrocatalysts for clean-energy diverse applications.

Designing Yolk-Shell Nanostructures for Reversible Water-Vapor-Responsive Dual-Mode Switching of Fluorescence and Structural Color.

Metal halide perovskites offer ample opportunities to develop advanced optoelectronic devices. This work showcases that the integration of metal halide perovskites into metal oxide nanoshells with controllable interior cavities can enable water-vapor-responsive dual-mode switching of fluorescence and structural color. Through a ship-in-a-bottle method to introduce a controlled amount of CsPbBr3 into MnO2 nanoshells, we have designed CsPbBr3@MnO2 yolk-shell nanostructures, which can uptake a defined amount of water to exhibit rapid (less than 1 s) and reversible (≥100 cycles) responses in both fluorescence on-off and color change when exposed to dynamic water vapor. These responses originate from the water-triggered phase transformation of CsPbBr3 to CsPb2Br5 and the structural color change of the MnO2 shell. The altered electronic and bonding structure at the oxide-halide interface, rapid water accumulation in the yolk-shell cavity, and protective effect of the oxide shell facilitate the reversible transformations. The response characteristics of the yolk-shell nanostructures have been further demonstrated in fabricating patterned films capable of multiple fluorescence/structural color responses, highlighting their potential for applications in advanced anticounterfeiting and encryption.

Yolk-shell nanospheres based silane-functionalized carbon dots: Designed synthesis and application in highly selective determination of aflatoxin biosynthesis-related genes nor-1 in cereal crops

This study presented advanced monitoring approaches for the aflatoxin gene cluster in Aspergillus flavus and Aspergillus parasiticus, which are effective tools for controlling aflatoxin proliferation in the food chain. A novel approach involved a ratiometric fluorescence probe based on yolk-shell nanospheres (bCDs@SiO2@gQDs). The probe's fluorescence was activated by DNA hybridization with the modified bCDs@SiO2@gQDs and gold nanoparticles (AuNPs), functioning through donor–acceptor pairs. The exceptional properties of the gQDs and the high FRET efficiency of this system established a functionalized platform for DNA labeling. When the nor-1 gene was present, FRET between the gQDs and AuNPs triggered fluorescence quenching, enabling nor-1 gene detection. The yolk-shell nanostructure of the fluorescent nanoprobes provided an internal reference, reducing experimental errors due to background noise, instrumentation factors, and probe concentration. This allowed for accurate and highly sensitive quantitative determination of the nor-1 gene. The ratiometric fluorescence assay demonstrated a broad linear range (0.1–100 nM) and a low detection limit (12.83 pM) for the nor-1 gene. Tests on non-contaminated maize samples spiked with various concentrations of the nor-1 gene achieved recovery rates between 95.43 % and 101.46 %. This biosensor represents a significant advancement in food safety, offering a simple, rapid, and sensitive method for monitoring agricultural products.

Active metals decorated NiCo2O4 yolk-shell nanospheres as nanoreactors for catalytic reduction of nitroarenes and azo dyes

Transition-metal oxides (TMOs) have received a great deal of research attention and have been widely used in a variety of fields. However, conventional TMOs do not possess high specific surface area, sufficient active site on their surfaces, and limited their applications in catalysis. This study presents a two-step method for synthesizing active metal (M) decorated NiCo2O4 (M/NiCo2O4, M = Pd or Cu) nanospheres with yolk-shell nanostructures. Taking advantage of the unique morphology and the combination of dual active components (i.e., active NiCo2O4 substrate and decorated active metal), the as-prepared M/NiCo2O4 yolk-shell nanospheres can be employed as nanoreactors in the organic reactions. In catalyzing the reduction of a representative nitroarene (i.e., 4-NP) by NaBH4, the Pd/NiCo2O4 nanoreactors exhibit a superior catalytic efficiency to their counterparts (Cu/NiCo2O4 and NiCo2O4). The turnover frequency is much higher than that of various TMOs supported nanocatalysts have been reported over the past five years. Furthermore, the Pd/NiCo2O4 nanoreactors show excellent stability and common applicability of the reduction of various substituted nitrobenzenes and azo dyes. This work provides new rational design concept and preparation strategy for efficient nanoreactors with dual active components and sheds light on the practical application of chemical reactions.

Fe3O4@void@C-Schiff-base/Pd yolk-shell nanostructures as an effective and reusable nanocatalyst for Suzuki coupling reaction

This article describes the synthesis of a novel Yolk-Shell structured Magnetic Yolk-Shell Nanomaterials Modified by Functionalized Carbon Shell with Schiff/Palladium Bases (Fe3O4@void@C-Schiff-base/Pd). The designed Fe3O4@void@C-Schiff-base/Pd catalyst was characterized using several techniques such as Fourier transform infrared spectroscopy (FTIR), vibrating sample magnetometry (VSM), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), thermal gravimetric analysis (TGA), powder X-ray diffraction (PXRD) and Inductively coupled plasma (ICP). The Fe3O4@void@C-Schiff-base/Pd was used as powerful catalyst for preparation Suzuki reaction in short reaction times and high yield in H2O at 60 °C and presence of potassium carbonate base. This nanocatalyst was magnetically recovered and reused several times with keeping its efficiency.

Tailor-made yolk-shell nanocomposites of star-shape Au and porous organic polymer for nitrogen electroreduction to ammonia

Electrocatalytic nitrogen (N2) reduction reaction (NRR) is an energy-saving approach to synthesize ammonia (NH3), which significantly depends on the development of high-efficiency electrocatalysts. Inspired by the catalytic microenvironment of enzymes, a series of yolk-shell nanostructures of monodispersed Au nanostars within porous organic polymers (POPs) have been successfully prepared via a self-sacrificing template strategy. The obtained yolk-shell nanocomposites have highly active Au nanostar cores and permeable POP shells for ambient electrocatalytic NRR to NH3. The hydrophobic properties of yolk-shell nanoreactors can be tailored accurately by engineering the POP shells at an atomic level, which greatly improves the N2 fixation performance by inhibiting the hydrogen evolution reaction, resulting in the unprecedented NH3 yield rate (∼109.1 μg h−1 mgcat.−1) and Faradaic efficiency (∼68.3 %). This work pioneers an effective strategy to construct tailor-made electrocatalysts for the N2-to-NH3 fixation.

Enhanced photocatalytic degradation of amoxicillin using a spinning disc photocatalytic reactor (SDPR) with a novel Fe3O4@void@CuO/ZnO yolk-shell thin film nanostructure

Antibiotics are resistant compounds with low biological degradation that generally cannot be removed by conventional wastewater treatment processes. The use of yolk-shell nanostructures in spinning disc photocatalytic reactor (SDPR) enhances the removal efficiency due to their high surface-to-volume ratio and increased interaction between catalyst particles and reactants. The purpose of this study is to investigate the SDPR equipped to Fe3O4@void@CuO/ZnO yolk-shell thin film nanostructure (FCZ YS) in the presence of visible light illumination in the photocatalytic degradation of amoxicillin (AMX) from aqueous solutions. Stober, co-precipitation, and self-transformation methods were used for the synthesis of FCZ YS thin film nanostructure and the physical and chemical characteristics of the catalyst were analyzed by XRD, VSM,, EDX, FESEM, TEM, AFM, BET, contact angle (CA), and DRS. Then, the effect of different parameters including pH (3–11), initial concentration of AMX (10–50 mg/L), flow rate (10–25 mL/s) and rotational speed (100–400 rpm) at different times in the photocatalytic degradation of AMX were studied. The obtained results indicated that the highest degradation efficiency of 97.6% and constant reaction rate of AMX were obtained under LED visible light illumination and optimal conditions of pH = 5, initial AMX concentration of 30 mg/L, solution flow rate of 15 mL/s, rotational speed of 300 rpm and illumination time of 80 min. The durability and reusability of the nanostructure were tested, that after 5 runs had a suitable degradation rate. Considering the appropriate efficiency of amoxicillin degradation by FCZ YS nanostructure, the use of Fe3O4@void@CuO/ZnO thin film in SDPR is suggested in water and wastewater treatment processes.

Synthesis of a Yolk-Shell Nanostructured Silicon-Based Anode for High-Performance Li-Ion Batteries

Silicon is a desirable anode material for Li-ion batteries owing to its remarkable theoretical specific capacity of over 4000 mAh/g. Nevertheless, the poor cycling performance of pure Si electrodes caused by dramatic volume expansion has limited its practical application. To alleviate the adverse effects of Si expansion, we have synthesized anode materials of nano-Si particles trapped in a buffering space and outer carbon-based shells (Si@Void@C). The volume ratio of Si nanoparticle to void space could be adjusted accurately to approximately 1:3, which maintained the structural integrity of the as-designed nanoarchitecture during lithiation/delithiation and achieved a notable specific capacity of ~750 mAh/g for as-prepared half-cells. The yolk-shell nanostructure alleviates volumetric expansion on both material and electrode levels, which enhances the rate performance and cycling stability of the silicon-based anode.

A general strategy for direct growth of yolk-shell MOF-on-MOF hybrids

Construction of metal–organic framework (MOF) hybrids with yolk-shell nanostructures via MOF-on-MOF growth is significant for MOF design toward elaborate properties and enhanced performances, while remains challenging. Here, we report the direct growth of yolk-shell MOF-on-MOF hybrids via an interfacial growth-reorganization strategy. The synthesis relies on the precise growth of guest CoZn-ZIF (ZIF = zeolite imidazole framework) with appropriate crystal diameter and arrangement on host MOFs, inducing an in-situ transformation of core–shell intermediate into yolk-shell product. This strategy can be generally applied to the growth of CoZn-ZIF onto various host MOFs with different shapes, crystal structures and compositions including rod-like and octahedral Fe-based NH2-MIL-88B (MIL = Material Institute Lavoisier) and cake-like Ti-based NH2-MIL-125 toward three kinds of yolk-shell MOF-on-MOF hybrids. Moreover, functional carbon materials with bridged yolk-shell architecture can be prepared by pyrolysis of MOF-on-MOF hybrids as precursors, exhibiting enhanced oxygen reduction reaction performance than their monomeric counterparts. Our work paves the way for the design and application of MOF based yolk-shell nanostructures.

Fabrication of a Novel Au Star@AgAu Yolk-Shell Nanostructure for Ovarian Cancer Early Diagnosis and Targeted Therapy.

A novel CYPA-targeted, SiO2 encapsulated Au star@AgAu yolk-shell nanostructure (YSNS) was synthesized and used for ovarian cancer early diagnosis and therapy. Diverse spectroscopic and microscopic methods were utilized to investigate the pattern of the yolk-shell nanostructure. In addition, in vitro and in vivo experiments were carried out. It can be found that the ratio of HAuCl4 and AgNO3 played a critical role in the constitution of the yolk-shell nanostructure. The as-prepared yolk-shell nanostructure showed excellent SERS performance, which could be utilized as SERS substrate for specific sensitivity analysis of ovarian cancer markers cyclophilin A (CYPA) with detectable limit of 7.76*10-10 μg/mL. In addition, the as-prepared yolk-shell nanostructure possessed outstanding photothermal performance, which could be used as photothermal agent for ovarian cancer therapy. Experiments in vitro and in vivo proved that the as-prepared yolk-shell nanostructures are ideal candidate for early diagnosis and therapy for ovarian cancer in one platform. This work holds promise to offer a new method for the detection and therapy of ovarian cancer in the early stage.

Unlocking Enhanced Capacitive Deionization of NaTi2(PO4)3/Carbon Materials by the Yolk–Shell Design

The low salt adsorption capacities (SACs) of benchmark carbon materials (usually below 20 mg g-1) are one of the most challenging issues limiting further commercial development of capacitive deionization (CDI), an energetically favorable method for sustainable water desalination. Sodium superionic conductor (NASICON)-structured NaTi2(PO4)3 (NTP) materials, especially used in combination with carbon to prepare NTP/C materials, provide emerging options for higher CDI performance but face the problems of poor cycling stability and dissolution of active materials. In this study, we report the development of the yolk-shell nanoarchitecture of NASICON-structured NTP/C materials (denoted as ys-NTP@C) using a metal-organic framework@covalent organic polymer (MOF@COP) as a sacrificial template and space-confined nanoreactor. As expected, ys-NTP@C exhibits good CDI performance, including exemplary SACs with a maximum SAC of 124.72 mg g-1 at 1.8 V in the constant-voltage mode and 202.76 mg g-1 at 100 mA g-1 in the constant-current mode, and good cycling stability without obvious performance degradation or energy consumption increase over 100 cycles. Furthermore, X-ray diffraction used to study CDI cycling clearly exhibits the good structural stability of ys-NTP@C during repeated ion intercalation/deintercalation processes, and the finite element simulation shows why yolk-shell nanostructures exhibit better performance than other materials. This study provides a new synthetic paradigm for preparing yolk-shell structured materials from MOF@COP and highlights the potential use of yolk-shell nanoarchitectures for electrochemical desalination.

Engineering of plasmonic metal-semiconductor yolk-shell nanostructures for multi-intensified photodynamic- and immuno- therapy against drug resistant bacteria

Photodynamic therapy (PDT) as well as immunotherapy are effective therapies to combat the systemic infection. Nevertheless, the development of the treatments are restrained by the lack of efficient photosensitizers (PS) and the genetic diversity of the bacteria. Here, we report Ag doped Au-CdS1−ySey yolk-shell nanostructures (AYSs) which exhibit excellent near-infrared (NIR) light induced PDT and immunotherapy performance. The tailored plasmonic Au nanorods (NRs) are able to gather the NIR light, offering the basis for PDT. Moreover, high yield of reactive oxygen species (ROS) is achieved through the following creativity: i) enhanced light trapping ability by the microcavity, ii) smooth injection process of hot electrons (HEs) by the suitable band gap alignment, iii) inhibiting the combination of electric charges by the doped Ag with appropriate concentration. Therefore, the AYSs exhibit more 30 times of ROS production as well as lower 64 times of MIC than the conventional core-shell nanostructures. Notably, repeated enhanced antibacterial PDT are carried out to obtain versatile antigens from various dead bacteria to awaken the immune cells adequately and boost immune response with the help of Selenium (Se) which is distributed in the shell. As a result, the systemic drug resistant bacterial infection is cured successfully.

Nitrogen-doped carbon encapsulated polyhedral ZnSe@CoSe2 yolk-shell nanostructures for high-efficiency oxygen evolution reaction

Designing non-noble metal oxygen evolution catalysts with outstanding catalytic activity is crucial for realizing cost-effective water splitting. In this paper, nitrogen-doped carbon-encapsulated polyhedral yolk-shell nanostructure bimetallic selenide (ZnSe@CoSe2/N-C) electrocatalyst was successfully prepared by high-temperature selenization strategy using ZIF-8 @ZIF-67 as the framework. The specially designed nitrogen-doped core-shell structure has the advantages of high specific surface area and rough porous surface, which can expose more active sites and facilitate the transfer of electrons and ions on the electrode surface. The high conductivity of ZnSe, CoSe2 nanoparticles and the synergistic effect of bimetal increase the electrochemical activity and electron mobility of the composite. ZnSe@CoSe2/N-C catalyst exhibits outstanding oxygen evolution reaction performance at 1.0 M KOH, which the overpotential is down to 170 mV at 10 mA cm−2. Furthermore, ZnSe@CoSe2/N-C also shows well durability and long-term stability (>113 h). This experiment might open a new path for fabrication of low-cost non-noble metal selenide electrocatalysts for oxygen evolution.

Oriented tuning yolk-shell structure for well-confinement and constructing durability of silicon/carbon composite

Silicon-based materials have been recognized as one of the most promising anode materials for next-generation lithium-ion batteries (LIBs) due to its high theoretical specific capacity (4200 mA h g−1), appropriate lithiation potential and abundance in earth. However, the fulsome volume swell and intrinsically low conductivity result in the sluggish kinetics and the limited cycle life, which severely hinders its commercial application. Herein, a composite of Si@hollow nitrogen-doped carbon (Si@HNC) with typical yolk-shell structure is designed and fabricated via a facile strategy coupled super-molecular self-assembly with carbonization. Benefiting from the buffering effect of yolk-shell nanostructure on the volumetric variation, and the excellent conductivity of the porous nitrogen-doped carbon shell, Si@HNC anode material exhibits high structural stability, fast charge and ion transfer. As a result, the Si@HNC sample with the Si content of 54.4 wt% delivers a reversible capacity of 865 mA h g−1 with the retention of ∼98 % at 1.0 A g−1 after 300 cycles. More surprisingly, a stable capacity of 1013 mA h g−1/3.24 mAh cm−2 is also retained at 0.5 A g−1 after 400 cycles even under the high areal loading of 3.2 mg cm−2.

Description of Photodegradation Mechanisms and Structural Characteristics in Carbon@Titania Yolk–Shell Nanostructures by XAS (Small 2/2023)

Carbon@Titania Yolk–Shell Nanostructures In article number 2203881, Shih-Yun Chen, Chi-Liang Chen, and co-workers use carbon@titania yolk-shell nanostructures for acetaminophen photocatalytic degradation in water. X-ray absorption spectroscopy discovers critical charge transfer processes and holes that formed in the p-d hybridized bands significantly enhance photodegradation ability under solar irradiation.