Ultra-sensitive H2S sensor based on sunflower-like In-doped ZnO with enriched oxygen vacancies.

Metal oxide sensors face the challenge of high response and fast recovery at low operating temperatures for the detection of toxic and flammable hydrogen sulfide (H2S) gases. Herein, novel In-doped ZnO with a sunflower-like structure and tunable surface properties was rationally synthesized. The substitutional In atom in the ZnO crystal can dramatically enhance the concentration of oxygen vacancies (Ov), the In-ZnO sites are responsible for fast recovery, and the formation of sub-stable sulfide intermediates gives rise to the high response towards H2S. As a result, the response of the optimized 4In-ZnO sensor is 3538.36 to 50 ppm H2S at a low operating temperature of 110 °C, which is 106 times higher than that of pristine ZnO. Moreover, the response time and recovery time to 50 ppm H2S are 100 s and 27 s, respectively, with high selectivity and stability. First-principles calculations revealed that 4In-ZnO with rich Ov exhibited higher adsorption energy for the H2S molecule than pristine ZnO, resulting in effortless H2S detection. Our work lays the foundation for the rational design of highly sensitive gas sensors through precise doping of atoms in oxygen-rich vacancies in semiconductor materials.

Cocrystallization Enabled Spatial Self-Confinement Approach to Synthesize Crystalline Porous Metal Oxide Nanosheets for Gas Sensing.

Crystalline metal oxide nanosheets show exceptional catalytic performance owing to the large surface-to-volume ratio and quantum confinement effect. However, it is still a challenge to develop a facile and general method to synthesize metal oxide nanosheets. Herein, we report a cocrystallization induced spatial self-confinement approach to synthesize metal oxide nanosheets. Taking the synthesis of SnO2 as an example, the solvent evaporation from KCl and SnCl2 solution induces the cocrystallization of KCl and K2 SnCl6 , and the obtained composite with encapsulated K2 SnCl6 can be in situ converted into SnO2 nanosheets confined in KCl matrix, after water washing to remove KCl, porous SnO2 nanosheets can be obtained. Notably, a series of metal oxide nanosheets can be obtained through this general and efficient green route. In particular, porous CeO2 /SnO2 nanosheets with improved surface O- species and abundant oxygen vacancies exhibit superior gas sensing performance to 3-hydroxy-2-butanone.

Structure Engineering of Yolk-Shell Magnetic Mesoporous Silica Microspheres with Broccoli-Like Morphology for Efficient Catalysis and Enhanced Cellular Uptake.

Yolk-shell magnetic mesoporous microspheres exhibit potential applications in biomedicine, bioseparation, and catalysis. Most previous reports focus on establishing various interface assembly strategies to construct yolk-shell mesoporous structures, while little work has been done to control their surface topology and study their relevant applications. Herein, a unique kind of broccoli-like yolk-shell magnetic mesoporous silica (YS-BMM) microsphere is fabricated through a surfactant-free kinetic controlled interface assembly strategy. The obtained YS-BMM microspheres possess a well-defined structure consisting of a magnetic core, middle void, mesoporous silica shell with tunable surface roughness, large superparamagnetism (36.4 emu g-1 ), high specific surface area (174 m2 g-1 ), and large mesopores of 10.9 nm. Thanks to these merits and properties, the YS-BMM microspheres are demonstrated to be an ideal support for immobilization of ultrafine Pt nanoparticles (≈3.7 nm) and serve as superior nanocatalysts for hydrogenation of 4-nitrophenol with yield of over 90% and good magnetic recyclability. Furthermore, YS-BMM microspheres show excellent biocompatibility and can be easily phagocytosed by osteoclasts, revealing a potential candidate in sustained drug release in orthopedic disease therapy.

Self-Hybrid Transition Metal Oxide Nanosheets Synthesized by a Facile Programmable and Scalable Carbonate-Template Method.

2D transition metal oxides (TMO) nanosheets have attracted considerable attention in both fundamental research and practical applications. Herein, a convenient programmable and scalable carbonate crystals templating synthesis is developed to produce high-quality self-hybrid TMO nanosheets (Si-WO3- x , Tax Oy , Mnx Oy ) and their respective polymetallic oxide hybrid nanosheets with tunable composition, low-cost and high-yield. Taking tungsten oxide nanosheets as example, silicotungstic acid precursor is in situ converted into tungsten oxide nanosheets like scales on the surface of calcium carbonate crystals through the simple soaking-drying-calcination process, and after selectively dissolving calcium carbonate by etching, the dispersive tungsten oxide nanosheets with unique self-hybrid Si-doped h-WO3 /ε-WO3 /WO2 compositions are obtained, which show excellent acetone gas-sensing performances at low temperatures. This carbonate-template method opens up the possibility to economically produce various functional TMO nanosheets with specific compositions for diverse applications.

Mesoporous Materials-Based Electrochemical Biosensors from Enzymatic to Nonenzymatic.

Mesoporous materials have drawn more and more attention in the field of biosensors due to their high surface areas, large pore volumes, tunable pore sizes, as well as abundant frameworks. In this review, the progress on mesoporous materials-based biosensors from enzymatic to nonenzymatic are highlighted. First, recent advances on the application of mesoporous materials as supports to stabilize enzymes in enzymatic biosensing technology are summarized. Special emphasis is placed on the effect of pore size, pore structure, and surface functional groups of the support on the immobilization efficiency of enzymes and the biosensing performance. Then, the development of a nonenzymatic strategy that uses the intrinsic property of mesoporous materials (carbon, silica, metals, and composites) to mimic the behavior of enzymes for electrochemical sensing of some biomolecules is discussed. Finally, the challenges and perspective on the future development of biosensors based on mesoporous materials are proposed.

Recent advances in amphiphilic block copolymer templated mesoporous metal-based materials: assembly engineering and applications.

Mesoporous metal-based materials (MMBMs) have received unprecedented attention in catalysis, sensing, and energy storage and conversion owing to their unique electronic structures, uniform mesopore size and high specific surface area. In the last decade, great progress has been made in the design and application of MMBMs; in particular, many novel assembly engineering methods and strategies based on amphiphilic block copolymers as structure-directing agents have also been developed for the "bottom-up" construction of a variety of MMBMs. Development of MMBMs is therefore of significant importance from both academic and practical points of view. In this review, we provide a systematic elaboration of the molecular assembly methods and strategies for MMBMs, such as tuning the driving force between amphiphilic block copolymers and various precursors (i.e., metal salts, nanoparticles/clusters and polyoxometalates) for pore characteristics and physicochemical properties. The structure-performance relationship of MMBMs (e.g., pore size, surface area, crystallinity and crystal structure) based on various spectroscopy analysis techniques and density functional theory (DFT) calculation is discussed and the influence of the surface/interfacial properties of MMBMs (e.g., active surfaces, heterojunctions, binding sites and acid-base properties) in various applications is also included. The prospect of accurately designing functional mesoporous materials and future research directions in the field of MMBMs is pointed out in this review, and it will open a new avenue for the inorganic-organic assembly in various fields.

Au Nanoparticles Decorated Mesoporous SiO2 -WO3 Hybrid Materials with Improved Pore Connectivity for Ultratrace Ethanol Detection at Low Operating Temperature.

Semiconducting metal oxides-based gas sensors with the capability to detect trace gases at low operating temperatures are highly desired in applications such as wearable devices, trace pollutant detection, and exhaled breath analysis, but it still remains a great challenge to realize this goal. Herein, a multi-component co-assembly method in combination with pore engineering strategy is proposed. By using bi-functional (3-mercaptopropyl) trimethoxysilane (MPTMS) that can co-hydrolyze with transition metal salt and meanwhile coordinate with gold precursor during their co-assembly with PEO-b-PS copolymers, ordered mesoporous SiO2 -WO3 composites with highly dispersed Au nanoparticles of 5 nm (mesoporous SiO2 -WO3 /Au) are straightforward synthesized. This multi-component co-assembly process avoids the aggregation of Au nanoparticles and pore blocking in conventional post-loading method. Furthermore, through controlled etching treatment, a small portion of silica can be removed from the pore wall, resulting in mesoporous SiO2 -WO3 /Au with increased specific surface area (129 m2  g-1 ), significantly improved pore connectivity, and enlarged pore window (>4.3 nm). Thanks to the presence of well-confined Au nanoparticles and ε-WO3 , the mesoporous SiO2 -WO3 /Au based gas sensors exhibit excellent sensing performance toward ethanol with high sensitivity (Ra /Rg = 2-14 to 50-250 ppb) at low operating temperature (150 °C).

Large-Pore Mesoporous CeO2 -ZrO2 Solid Solutions with In-Pore Confined Pt Nanoparticles for Enhanced CO Oxidation.

Active and stable catalysts are highly desired for converting harmful substances (e.g., CO, NOx ) in exhaust gases of vehicles into safe gases at low exhaust temperatures. Here, a solvent evaporation-induced co-assembly process is employed to design ordered mesoporous Cex Zr1- x O2 (0 ≤ x ≤ 1) solid solutions by using high-molecular-weight poly(ethylene oxide)-block-polystyrene as the template. The obtained mesoporous Cex Zr1- x O2 possesses high surface area (60-100 m2 g-1 ) and large pore size (12-15 nm), enabling its great capacity in stably immobilizing Pt nanoparticles (4.0 nm) without blocking pore channels. The obtained mesoporous Pt/Ce0.8 Zr0.2 O2 catalyst exhibits superior CO oxidation activity with a very low T100 value of 130 °C (temperature of 100% CO conversion) and excellent stability due to the rich lattice oxygen vacancies in the Ce0.8 Zr0.2 O2 framework. The simulated catalytic evaluations of CO oxidation combined with various characterizations reveal that the intrinsic high surface oxygen mobility and well-interconnected pore structure of the mesoporous Pt/Ce0.8 Zr0.2 O2 catalyst are responsible for the remarkable catalytic efficiency. Additionally, compared with mesoporous Pt/Cex Zr1- x O2 -s with small pore size (3.8 nm), ordered mesoporous Pt/Cex Zr1- x O2 not only facilitates the mass diffusion of reactants and products, but also provides abundant anchoring sites for Pt nanoparticles and numerous exposed catalytically active interfaces for efficient heterogeneous catalysis.

A General and Straightforward Route to Noble Metal-Decorated Mesoporous Transition-Metal Oxides with Enhanced Gas Sensing Performance.

Controllable and efficient synthesis of noble metal/transition-metal oxide (TMO) composites with tailored nanostructures and precise components is essential for their application. Herein, a general mercaptosilane-assisted one-pot coassembly approach is developed to synthesize ordered mesoporous TMOs with agglomerated-free noble metal nanoparticles, including Au/WO3 , Au/TiO2 , Au/NbOx , and Pt/WO3 . 3-mercaptopropyl trimethoxysilane is applied as a bridge agent to cohydrolyze with metal oxide precursors by alkoxysilane moieties and interact with the noble metal source (e.g., HAuCl4 and H2 PtCl4 ) by mercapto (SH) groups, resulting in coassembly with poly(ethylene oxide)-b-polystyrene. The noble metal decorated TMO materials exhibit highly ordered mesoporous structure, large pore size (≈14-20 nm), high specific surface area (61-138 m2 g-1 ), and highly dispersed noble metal (e.g., Au and Pt) nanoparticles. In the system of Au/WO3 , in situ generated SiO2 incorporation not only enhances their thermal stability but also induces the formation of ε-phase WO3 promoting gas sensing performance. Owning to its specific compositions and structure, the gas sensor based on Au/WO3 materials possess enhanced ethanol sensing performance with a good response (Rair /Rgas = 36-50 ppm of ethanol), high selectivity, and excellent low-concentration detection capability (down to 50 ppb) at low working temperature (200 °C).

Study on the anti-slide mechanism of double-row circular pile by model test using PIV, transparent soil material and 3D printing technology.

Landslides are common geological hazards that cause significant losses. Anti-slide piles are commonly used in landslide engineering, and model testing is one of the means to study pile-supported structures. However, model tests face several challenges, including difficulty in controlling the experimental process, challenges in repeated tests, and difficulty in monitoring soil deformation around piles. To address these issues, this study presents a model test method using particle image velocimetry (PIV), transparent soil, and 3D printing technology. Using this method, a series of model tests were conducted, including single-row and double-row anti-slide piles. The experimental results indicate that, compared with single-row piles, double-row piles exhibit better supporting effects. In the pile‒soil interaction, the displacement of the extrusion of soil between piles was controlled under the combined action of the front and back rows of piles. The inclination angle of a single-row pile after the test was 8°, whereas that of a double-row pile was reduced by 62.5%. With respect to the displacement of the soil behind the piles, the phenomenon of a "displacement triangle" behind the piles was observed. An analysis of the change process in this area revealed that the relative displacement caused by pile‒soil interactions is mainly distributed in the surface layer of the soil. The experiments demonstrate that this system is suitable for pile-supported structure model tests.

Deformation characteristics of overlying strata in room and pillar mined-out areas under coal pillar instability.

Under the condition of small roof deformation before the occurrence of fractures and collapse in room and pillar mined-out areas caused by coal pillar instability, the surface deformation may be large, which threatens the safety of ground structures. Interferometric synthetic aperture radar, geophysical exploration, geotechnical exploration and physical simulation tests were conducted to analyse the deformation and development mechanism of the overlying strata in the mined-out area in this case. The results show that in terms of surface deformation, the surface deformation caused by coal pillar instability in the room and pillar mined-out area exhibits the slow deformation stage, uniform deformation stage and accelerated deformation stage. In terms of deformation of overlying strata, after the completion of room and pillar mining, a strip-shaped deformation area and trapezoidal deformation area are developed in the overlying rock. With the occurrence of coal pillar instability, a trapezoidal deformation area and inverted funnel-shaped deformation area are developed in the overlying rock. The deformation characteristics of unconsolidated formations transition from trapezoidal deformation after room and pillar mining to funnel-shaped deformation due to coal pillar instability. Moreover, the maximum surface deformation point is located at the centre of the funnel. In terms of spatial morphology of mined-out area deformation, the maximum surface deformation point corresponds to the position of the initial coal pillar instability and the crack in the mined-out area roof along the vertical direction. The mined-out area treatment method can be optimized based on the deformation characteristics of the overlying strata in the room and pillar mined-out area under the condition of coal pillar instability.

Oxygen Vacancy Enabled Electronic Structure Engineering of Pt-WO3 Nanosheets toward Highly Efficient BTEX Sensing.

A Pt nanoparticle-immobilized WO3 material is a promising candidate for catalytic reactions, and the surface and electronic structure can strongly affect the performance. However, the effect of the intrinsic oxygen vacancy of WO3 on the d-band structure of Pt and the synergistic effect of Pt and the WO3 matrix on reaction performance are still ambiguous, which greatly hinders the design of advanced materials. Herein, Pt-decorated WO3 nanosheets with different electronic metal-support interactions are successfully prepared by finely tuning the oxygen vacancy structure of WO3 nanosheets. Notably, Pt-modified WO3 nanosheets annealed at 400 °C exhibit excellent benzene series (BTEX) sensing performance (S = 377.33, 365.21, 348.45, and 319.23 for 50 ppm ethylbenzene, benzene, toluene, and xylene, respectively, at 140 °C), fast response and recovery dynamics (10/7 s), excellent reliability (σ = 0.14), and sensing stability (φ = 0.08%). Detailed structural characterization and DFT results reveal that interfacial Ptδ+-Ov-W5+ sites are recognized as the active sites, and the oxygen vacancies of the WO3 matrix can significantly affect the d-band structure of Pt nanoparticles. Notably, Pt/WO3-400 with improved surface oxygen mobility and medium electronic metal-support interaction facilitates the activation and desorption of BTEX, which contributes to the highly efficient BTEX sensing performance. Our work provides a new insight for the design of high-performance surface reaction materials for advanced applications.

The in situ phosphorization inducing oxygen vacancies in the core-shell structured NiFe oxides boosts the electrocatalytic activity for the oxygen evolution reaction.

Transition metal-based oxides have been reported as an important family of electrocatalysts for water splitting owing to their possible large-scale applications that are highly desirable for the hydrogen generation industry. Herein, we report a facile method for the preparation of phosphate-decorated NiFe oxides on nickel foam as efficient oxygen evolution reaction (OER) electrocatalysts for water oxidation. The OER electrocatalysts were developed through the pyrolysis of MIL(Fe) metal-organic frameworks (MOFs), which were modified with Ni and P species. It was found that the formation of NiO on the Fe2O3 surface (NiO@Fe2O3) can enrich electrocatalytic active sites for the OER. Meanwhile, the incorporation of P into NiO@Fe2O3 (Px-NiO@Fe2O3) creates abundant oxygen vacancies, which facilitates the surface charge transfer for OER electrocatalysis. Benefiting from the structure and composition advantages, P2.0-NiO@Fe2O3/NF exhibits the best performance for OER electrocatalysis among other prepared electrocatalysts, with an overpotential of 208 mV at the OER current density of 10 mA cm-2 and a small Tafel slope of 69.64 mV dec-1 in 1 M KOH solution. Additionally, P2.0-NiO@Fe2O3/NF shows an outstanding durability for the OER electrocatalysis, maintaining the OER current density above 20 mA cm-2 for more than 100 h.

Research on the utilization of ultra-long carbon nanotubes in lithium-ion batteries based on an environment-friendly society.

To build an environment-friendly society, clean transportation systems, and renewable energy sources play essential roles. It is critical to improve the lifetime mileage of electric vehicles' batteries for reducing the cycle life cost and carbon footprint in green transportation. In this paper, a long-life lithium-ion battery is achieved by using ultra-long carbon nanotubes (UCNTs) as a conductive agent with relatively low content (up to 0.2% wt.%) in the electrode. Ultra-long CNT could realize longer conductive path crossing active material bulks in the electrode. Meanwhile, the low content of UCNTs can help to minimize conductive agent content in electrodes and obtain higher energy density. The film resistance and electrochemical impedance spectroscopy (EIS) confirmed that the use of UCNTs could markedly enhance electronic conductivity in the battery. The battery's life and life mileage can be prolonged by almost half due to the superior electronic conductivity of UCNTs. The life cycle cost and carbon footprint are also significantly reduced, which could markedly increase economic and environmental performance.

Pd Decoration with Synergistic High Oxygen Mobility Boosts Hydrogen Sensing Performance at Low Working Temperature on WO3 Nanosheet.

Pd-based materials have received remarkable attention and exhibit excellent H2 sensing performance due to their superior hydrogen storage and catalysis behavior. However, the synergistic effects originated from the decoration of Pd on a metal oxide support to boost the sensing performance are ambiguous, and the deep investigation of metal support interaction (MSI) on the H2 sensing mechanism is still unclear. Here, the model material of Pd nanoparticle-decorated WO3 nanosheet is synthesized, and individual fine structures can be achieved by treating it at different temperatures. Notably, the Pd-WO3-300 materials display superior H2 sensing performance at a low working temperature (110 °C), with a superior sensing response (Ra/Rg = 40.63 to 10 ppm), high sensing selectivity, and anti-interference ability. DFT calculations and detailed structural investigations confirm that the moderate MSI facilitates the generation of high mobility surface O2- (ad) species and a proper ratio of surface Pd0-Pd2+ species, which can significantly boost the desorption of intermediate PdHx species at low temperatures and contribute to enhanced sensing performance. Our work illustrates the effect of MSI on sensing performance and provides insight into the design of advanced sensing materials.

Apomictic Malus plants exhibit abnormal pollen development.

Apomixis is the asexual reproduction through seeds that leads to the production of genetically uniform progeny. It has become an important tool in plant breeding because it facilitates the retention of genotypes with desirable traits and allows seeds to be obtained directly from mother plants. Apomixis is rare in most economically important crops, but it occurs in some Malus species. Here, the apomictic characteristics of Malus were examined using four apomictic and two sexually reproducing Malus plants. Results from transcriptome analysis showed that plant hormone signal transduction was the main factor affecting apomictic reproductive development. Four of the apomictic Malus plants examined were triploid, and pollen was either absent or present in very low densities in the stamen. Variation in the presence of pollen was associated with variation in the apomictic percentage; specifically, pollen was absent in the stamens of tea crabapple plants with the highest apomictic percentage. Furthermore, pollen mother cells failed to progress normally into meiosis and pollen mitosis, a trait mostly observed in apomictic Malus plants. The expression levels of meiosis-related genes were upregulated in apomictic plants. Our findings indicate that our simple method of detecting pollen abortion could be used to identify apple plants that are capable of apomictic reproduction.

Functionalization of Mesoporous Semiconductor Metal Oxides for Gas Sensing: Recent Advances and Emerging Challenges.

With the emerging of the Internet of Things, chemiresistive gas sensors have been extensively applied in industrial production, food safety, medical diagnosis, and environment detection, etc. Considerable efforts have been devoted to improving the gas-sensing performance through tailoring the structure, functions, defects and electrical conductivity of sensitive materials. Among the numerous sensitive materials, mesoporous semiconductor metal oxides possess unparalleled properties, including tunable pore size, high specific surface area, abundant metal-oxygen bonds, and rapid mass transfer/diffusion behavior (Knudsen diffusion), which have been regarded as the most potential sensitive materials. Herein, the synthesis strategies for mesoporous metal oxides are overviewed, the classical functionalization techniques of sensitive materials are also systemically summarized as a highlight, including construction of mesoporous structure, regulation of micro-nano structure (i.e., heterojunctions), noble metal sensitization (e.g., Au, Pt, Ag, Pd) and heteroatomic doping (e.g., C, N, Si, S). In addition, the structure-function relationship of sensitive materials has been discussed at molecular-atomic level, especially for the chemical sensitization effect, elucidating the interface adsorption/catalytic mechanism. Moreover, the challenges and perspectives are proposed, which will open a new door for the development of intelligent gas sensor in various applications.

Unusual Role of the Surfactant in the Self-Assembly of Pt Alloy in Ordered Mesoporous Carbon: Tuning the Nanocluster Size.

In the one-step self-assembly synthesis of metallic nanocrystals in ordered mesoporous carbon (OMC), the surfactant functionalizes well as the structure directing agent and mesopore template. Interestingly, this work demonstrates another unusual role the surfactant plays: tuning the size of the nanocrystals. Our investigation shows that the decreasing molecular weight of the PS segment of PEO-b-PS leads to sequentially reduced PtRu particle sizes of 4.4, 3.9, and 2.9 nm, while F127 which has a distinctly smaller hydrophobic PO domain with a bending structure in the micelles successfully results in sub-2 nm PtM (M = Ru, Ir, Rh, Pd) nanoclusters in OMC. This well indicates that the nanocluster size is largely decided by the volume of the hydrophobic segment of the surfactant to which the metallic precursor is linked. The smaller the volume, the fewer the precursor molecules are adsorbed, and the smaller the alloy nanoclusters. In the electrocatalytic methanol oxidation reaction, the mass activity of PtRu-1.6/OMC with 1.6 nm PtRu clusters at 0.87 V reaches 1.07 A mgPt-1, which is 2.9 times that of commercial PtRu/C with an average alloy size of 2.7 nm. In principle, a wide range of ultrafine metallic clusters embedded in OMC can be prepared via this route for various applications.

Size-Controlled Au Nanoparticles Incorporating Mesoporous ZnO for Sensitive Ethanol Sensing.

Zinc oxide (ZnO) as a commonly used semiconductor material has aroused extensive research attention in various fields, such as field-effect transistors, solar cells, luminescent devices, and sensors, because of its excellent light-electrical features and large exciton bonding energy. Herein, ultrasmall Au nanoparticles with tunable size decorated mesoporous ZnO nanospheres were synthesized via facile formaldehyde-assisted metal-ligand cross-linking strategy, where these active Au species could be transferred into Au nanoparticles in the frameworks by various reduction strategies. Typically, mesoporous ZnO-Au with a photoreduction technique showed superior ethanol sensing performance (ca. 159 for 50 ppm at 200 °C) because of its high surface area, dual-mesoporous structure, and interface effect (electron effect, surface catalytic/adsorption). Moreover, the mesoporous ZnO-Au composites by photoreduction show much better performance than those via H2 reduction and NaBH4 reduction, which is ascribed to the providential size of Au nanoparticles (ca. 6.6 nm) and abundant oxygen defects in the composites. In particular, the selectivity and sensitivity of mesoporous ZnO-Au far exceeds those of materials loaded with other noble metals (Pt, Pd, and Ag). The sensing mechanism of mesoporous ZnO-Au for ethanol is attributed to classical surface adsorption/catalytic reaction, where strong sensitization effect (electron and chemical) and the spillover effect of Au nanoparticles in the catalytic reaction cause superior ethanol sensing performances. In situ FTIR and GC-MS measurement revealed that the catalytic oxidation of ethanol follows the process of dehydrogenation and deep oxidation, that is, dehydrogenation to acetaldehyde, and then further oxidation to carbon dioxide and water.

Smart Cargo Delivery System based on Mesoporous Nanoparticles for Bone Disease Diagnosis and Treatment.

Bone diseases constitute a major issue for modern societies as a consequence of progressive aging. Advantages such as open mesoporous channel, high specific surface area, ease of surface modification, and multifunctional integration are the driving forces for the application of mesoporous nanoparticles (MNs) in bone disease diagnosis and treatment. To achieve better therapeutic effects, it is necessary to understand the properties of MNs and cargo delivery mechanisms, which are the foundation and key in the design of MNs. The main types and characteristics of MNs for bone regeneration, such as mesoporous silica (mSiO2 ), mesoporous hydroxyapatite (mHAP), mesoporous calcium phosphates (mCaPs) are introduced. Additionally, the relationship between the cargo release mechanisms and bone regeneration of MNs-based nanocarriers is elucidated in detail. Particularly, MNs-based smart cargo transport strategies such as sustained cargo release, stimuli-responsive (e.g., pH, photo, ultrasound, and multi-stimuli) controllable delivery, and specific bone-targeted therapy for bone disease diagnosis and treatment are analyzed and discussed in depth. Lastly, the conclusions and outlook about the design and development of MNs-based cargo delivery systems in diagnosis and treatment for bone tissue engineering are provided to inspire new ideas and attract researchers' attention from multidisciplinary areas spanning chemistry, materials science, and biomedicine.