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Sodium-ion hybrid capacitor (SIHC) is one of the most promising alternatives for large-scale energy storage due to its high energy and power densities, natural abundance, and low cost. However, overcoming the imbalance between slow Na+ reaction kinetics of battery-type anodes and rapid ion adsorption/desorption of capacitive cathodes is a significant challenge. Here, we propose the high-rate-performance NiS2@OMGC anode material composed of monodispersed NiS2 nanocrystals (8.8 ± 1.7 nm in size) and N, S-co-doped graphenic carbon (GC). The NiS2@OMGC material has a three-dimensionally ordered macroporous (3DOM) morphology, and numerous NiS2 nanocrystals are uniformly embedded in GC, forming a core–shell structure in the local area. Ultrafine NiS2 nanocrystals and their nano–microstructure demonstrate high pseudocapacitive Na-storage capability and thus excellent rate performance (355.7 mAh/g at 20.0 A/g). A SIHC device fabricated using NiS2@OMGC and commercial activated carbon (AC) cathode exhibits ultrahigh energy densities (197.4 Wh/kg at 398.8 W/kg) and power densities (43.9 kW/kg at 41.3 Wh/kg), together with a long life span. This outcome exemplifies the rational architecture and composition design of this type of anode material. This strategy can be extended to the design and synthesis of a wide range of high-performance electrode materials for energy storage applications.

Gradient distribution of functional components endows PAN-based CPE with particular function. MoP/MoS2@C specialized in S adsorption and LiTFSI salt for Li+ supply boost Li2S conversion. The concentrated PMMA helps Li anode exhibit a uniform morphology.

MnOx–NiOx/C composite bidirectionally catalyzes LiPS reduction and Li2S oxidation via constructing a thiosulfate-mediating reaction path beyond the common route. These intensified Li2Sx (x ≤ 4) redox reactions promote long-term cycling.

Nanostructured integrated electrodes with binder-free design show great potential to solve the ever-growing problems faced by currently commercial lithium-ion batteries such as insufficient power and energy densities. However, there are still many challenging problems that limit the practical application of this emerging technology, in particular complex manufacturing process, high fabrication cost, and low loading mass of active material. Different from those existing fabrication strategies, here using a Co-P alloy foil as precursor we demonstrate a simple neutral salt solution-mediated electrochemical dealloying method to well address the above issues. The resultant freestanding mesoporous np-Co(OH)

A solid-state composite polymer electrolyte comprising Li

Neither of the two widely used staging models in the long history of intercalation chemistry, namely the classical Rüdorff-Hofmann model proposed in 1938 and the pleated-layer domain-modified one in 1969, can explain the intercalation reaction phenomena and mechanism logically. Taking the landmark potassium-intercalation reaction of graphite as a model case and two advanced monolithic graphitic/graphenic carbon foams as model electrodes, here we have revealed that the electrochemical storage of potassium in graphitic/graphenic carbon (as that of lithium) obeys a simple interlayered centroid intercalation (ICIC) rule to achieve the staged potassium intercalation into each graphitic interlayer: C → KC72 → KC24 → KC8. Moreover, judging from the typical potassium-storage behaviors and crystal texture of graphitic electrodes, nitrogen doping and pre-embedded K atoms would enable incoming K+ ions to perform fast pseudocapacitive diffusion in graphitic gallery. This study not only makes clear the basic K-storage mechanism and phenomena in graphitic carbon, but also establishes a more reasonable ICIC model for intercalation chemistry, and thus may help open a new research era for this field as well as graphite-based metal-ion batteries.

Core-sheath hierarchical-architectured materials have attracted much attention due to their extensive application in energy storage devices. However, as to multi-dimensional hierarchical core-sheath architectures, relative study has rarely been reported. In this work, a unique sugar gourd-like architecture is designed for the first time with hollow Co-Ni LDH nanocages uniformly strung by MnO2 nanowire (MnO2@Co-Ni LDH). Meanwhile, its forming mechanism is also systematically studied. Beneficial from this unique architecture, the designed MnO2@Co-Ni LDH possesses highly micro-structural integrity, abundant electrochemical-active sites and developed 3D diffusion path for electrolyte ions. When evaluated as positive electrode for pseudocapacitor, this material exhibits large specific capacitance of 1436 F g−1 at a current density of 1 A g−1, excellent rate capability (e.g., 1080 F g−1 at 20 A g−1) and high cycling stability (96.1% retention after 10,000 cycles). To assess practical functionality, a hybrid supercapacitor based on MnO2@Co-Ni LDH and active carbon nanoparticle is fabricated, which exhibits a high energy density of 40.9 Wh kg−1 along with remarkable long-term cyclic stability (81.8% retention after 20,000 cycles), demonstrating its potential application in the feld of energy storage devices. More importantly, the novel structural design can be easily extended to the synthesis of other functional materials for widespread applications.

This paper reports a method for the preparation of glass by reflowing commercial mixed micro and nano powders. High-quality micro-structure glass is formed by a microfabrication process combined with reflow process of the mixed micro and nano powders. The quality of glass prepared by different components was investigated and analyzed. Characterization of the formed glass micro-structure was performed by combining scanning electrical microscopy, energy dispersive spectroscopy, x-ray diffraction, and x-ray photoelectron spectroscopy. The glass reflow results were compared with the anodic bonding sample, which showed micro-structure glass prepared by our method was well-formed with high density and transparency. These results may inspire new possibilities for glass-based microsystems and MEMS applications.

Two-dimensional (2D) materials with mono or few layers have wide application prospects, including electronic, optoelectronic, and interface functional coatings in addition to energy conversion and storage applications. However, the exfoliation of such materials is still challenging due to their low yield, high cost, and poor ecological safety in preparation. Herein, a safe and efficient solid suspension-improving method was proposed to exfoliate hexagonal boron nitride nanosheets (hBNNSs) in a large yield. The method entails adding a permeation barrier layer in the solvothermal kettle, thus prolonging the contact time between the solvent and hexagonal boron nitride (hBN) nanosheet and improving the stripping efficiency without the need for mechanical agitation. In addition, the proposed method selectively utilizes a matching solvent that can reduce the stripping energy of the material and employs a high-temperature steam shearing process. Compared with other methods, the exfoliating yield of hBNNSs is up to 42.3% at 150 °C for 12 h, and the strategy is applicable to other 2D materials. In application, the ionic conductivity of a PEO/hBNNSs composite electrolytes reached 2.18 × 10−4 S cm−1 at 60 °C. Overall, a versatile and effective method for stripping 2D materials in addition to a new safe energy management strategy were provided.

As a very promising energy storage device, aqueous Zn-ion battery (ZIB) has made great progress recently. However, the selection of cathode active material remains a major difficulty in this battery system. Here, a kind of low-cost, non-toxic, environmentally friendly, nano-scaled γ-Fe2O3 with natural cation vacancies is demonstrated as an effective cathode material for aqueous zinc batteries. The electrochemical reaction mechanisms of the Zn/γ-Fe2O3 system in two common electrolytes, 2 M ZnSO4 aqueous solution and 3 M Zn(CF3SO3)2 aqueous solution, are explored. The H+ insertion mechanism and H+/Zn2+ co-insertion mechanism are defined in these two battery systems, respectively. Furthermore, it is found that the addition of highly concentrated magnesium ions in the electrolyte can effectively inhibit the formation of hydrated zinc hydroxide during the discharge process and improve the electrochemical performance of the battery. Whether in 1.5 M MgSO4 + 0.5 M ZnSO4 aqueous solution or in 2.5 M Mg(CF3SO3)2 + 0.5 M Zn(CF3SO3)2 aqueous solution, both of these two Zn/γ-Fe2O3 battery systems exhibit good rate performance. This work provides more possibilities for the development of iron-based cathode materials.

Although hard carbons holds the most promise as anodes for practical sodium-ion batteries, high cost and low initial coulomb efficiency (ICE) limit their commercial application. In the present work, we develop an efficient solvothermal stabilization method to fabricate hard carbon spheres with high carbon yield from the wheat starch precursor. As anode for sodium-ion batteries, the obtained samples deliver not only a high capacity above 300 mAh g−1, but also an enhanced initial coulombic efficiency up to 90% and long cycle stability. Furthermore, when coupled with Na0.9[Cu0.22Fe0.30Mn0.48]O2 as cathode electrode, the full cell exhibited a high ICE of 85%, an average voltage of 3.2V and excellent stability during 300 cycles charging and discharging. These desirable electrochemical performances, combined with the renewable precursor and efficient synthesis route, make the obtained hard carbon sphere a promising anode for practical material for sodium-ion batteries.

Through effectively harvesting and converting solar energy, photocatalysis has become one of the most important technologies in wastewater decontamination and hydrogen production. Currently, extensive studies are being conducted to develop photocatalysts with advanced features, such as visible-light response, heterogeneous nanoarchitecture, plasmonic effect, and excellent optical behavior. Finding efficient utilization technique to improve photocatalytic performance motivates researchers all over the world. Herein, we demonstrate the design of a visible-light-driven Pd/Fe2O3/BiVO4 hybrid with 3D ordered macro-/mesoporous (3DOM) nanoarchitecture for efficiently photocatalytic organic degradation and photoelectrochemical (PEC) water splitting. The hybrid photocatalyst exhibited two-tier bandgap energies and possessed enhanced ability to harvest visible light and separate photo-induced carriers. It is shown that, over the Pd/Fe2O3/3DOM-BiVO4 photocatalyst, not only the refractory phenol could be rapidly degraded into CO2 and H2O, but also the photoconversion efficiency was greatly improved in water splitting to generate H2. The excellent photocatalytic performance of Pd/Fe2O3/BiVO4 was associated with the construction of low-crystalline plasmonic heterointerfaces through the 3DOM framework. The produced synergistic action enabled the hybrid material to absorb the sunlight adequately and transfer the photoexcited carriers expediently to drive phenol degradation or hydrogen evolution from water.

The real capacity of graphene and the lithium-storage process in graphite are two currently perplexing problems in the field of lithium ion batteries. Here we demonstrate a three-dimensional bilayer graphene foam with few defects and a predominant Bernal stacking configuration, and systematically investigate its lithium-storage capacity, process, kinetics, and resistances. We clarify that lithium atoms can be stored only in the graphene interlayer and propose the first ever planar lithium-intercalation model for graphenic carbons. Corroborated by theoretical calculations, various physiochemical characterizations of the staged lithium bilayer graphene products further reveal the regular lithium-intercalation phenomena and thus fully illustrate this elementary lithium storage pattern of two-dimension. These findings not only make the commercial graphite the first electrode with clear lithium-storage process, but also guide the development of graphene materials in lithium ion batteries., The mechanism of lithium storage in graphenic carbon remains a fundamental question to be addressed. Here the authors employ suitable bilayer graphene foam to investigate various physiochemical phenomena of lithium intercalation and propose a storage model.

We report a successful growth of groove-like NiMoO4 hollow nanorods (NiMoO4-GHRs) via a facile and efficient one-pot hydrothermal approach, and test them as positive electrode materials for pseudocapacitors. We demonstrate that such hollow nanorods with a high aspect ratio (nearly ∼104) show a large specific surface area and electroactive surface area, giving rise to good electrochemical performance. Especially, the NiMoO4-GHRs electrode shows a high specific capacitance of 1102.2 F g−1 at a current density of 1 A g−1, a good rate capability by having 64.5% retention at a high current density of 20 A g−1, and an excellent cycling stability by retaining 90% of its original state even after 1000 cycles. The NiMoO4-GHRs with unique structures and enhanced electrochemical functionalities should be a promising electrode material for high-performance supercapacitors.

Graphene material is promising for harmonizing supercapacitor-like power density and battery-level energy density into one electrochemical energy storage (EES) system. Cost-effective, controlled, and massive production of graphene material and its successful application in practical EES are two significant challenges yet to be resolved. By developing a simple nickel nitrate-based hard-template preparation, this study demonstrates the smart design of nanocrystalline C-Ni hybrid monoliths with three-dimensionally ordered macroporous (3DOM) frameworks for high-efficiency EES. The abundant Li-storage sites and mixed high electronic and ionic conductivities grant such freestanding C-Ni composite electrode material large reversible capacity and high-rate capability through thousands of cycles even at a great thickness and using no extra current collector. This 3DOM strategy will facilitate real EES applications of graphene materials, and the yielded nanocrystalline-graphene material is promising to replace graphite anodes in current commercial LIBs with limited performances.

Three-dimensionally ordered macroporous (3DOM) photocatalysts BiVO4 (denoted as 3D-BiV), AgBr/3D-BiV, and 0.17 wt% M/AgBr/3D-BiV (M Au, Pt, and Pd) were prepared using the polymethyl methacrylate-templating, low-temperature deposition, and polyvinyl alcohol-protected reduction methods, respectively. The as-prepared BiVO4 possessed a good-quality 3DOM structure and a high surface area. It is found that the AgBr and noble metals were uniformly distributed on the surface of 3D-BiV. Among the M/AgBr/3D-BiV samples, the 0.17 wt% Pd/AgBr/3D-BiV sample showed the highest photocatalytic activity for the degradation of 4-chlorophenol (4-CP) under visible light illumination (i.e., complete 4-CP degradation could be achieved within 150 min), which was associated with its good 3DOM structure, high surface oxygen adspecies concentration, easy transfer and separation of photogenerated carriers, and synergistic effect between AgBr or Pd nanoclusters and BiVO4.

Three-dimensionally ordered macroporous (3DOM) InVO 4 –BiVO 4 (InBi-3D) and its supported noble metal M nanoparticles ( x M/InBi-3D; x = 0.08–0.13 wt%; M = Au, Ag, Pd, Pt) were prepared using the polymethyl methacrylate-templating and polyvinyl alcohol- or polyvinyl pyrrolidone-assisted reduction methods, respectively. Physical properties of the materials were characterized by a number of analytical techniques. Photocatalytic activities of the x M/InBi-3D samples were evaluated for the degradation of rhodamine B (RhB), methylene blue (MB), and their mixture. It is found that the as-fabricated samples possessed a surface area of 17–30 m 2 /g, a M particle size of 2.5–3.8 nm, and a bandgap energy of 2.50–2.56 eV. The x M/InBi-3D photocatalysts showed high activities for the degradation of RhB, MB, and RhB + MB in the presence of a small amount of H 2 O 2 under visible-light irradiation, among which complete degradation of RhB, MB, and RhB + MB was achieved within 50, 90, and 120 min over 0.08 wt% Au/InBi-3D, respectively. The degradation of MB and RhB fellow the zero- and first-order reaction mechanisms with respect to dye concentration, respectively. It is concluded that the high photocatalytic efficiency of the Au-loaded sample in the removal of organic dyes was associated with its high surface area, high-quality 3DOM hierarchical architecture, InVO 4 –BiVO 4 composite, and high dispersion of gold nanoparticles.

Three-dimensionally ordered macro/mesoporous Ce0.6Zr0.3Y0.1O2 (3DOM CZY) supported high-dispersion Pt nanoparticles (x wt % Pt/3DOM CZY, x = 0.6, 1.1, and 1.7) were successfully synthesized via the cetyltrimethylammonium bromide/triblock copolymer P123 assisted gas bubbling reduction route. The 3DOM CZY and x wt % Pt/3DOM CZY samples exhibited a high surface area of 84–94 m2/g. Pt nanoparticles (NPs) with a size of 2.6–4.2 nm were uniformly dispersed on the surface of 3DOM CZY. The 1.1 wt % Pt/3DOM CZY sample showed excellent catalytic performance, giving a T90% value at 598 °C at gas hourly space velocity (GHSV) of 30000 mL/(g h) and the highest turnover frequency (TOFPt) of 6.98 × 10–3 mol/(molPt s) at 400 °C for methane combustion. The apparent activation energy (64 kJ/mol) over 1.1 wt % Pt/3DOM CZY was much lower than that (95 kJ/mol) over Bulk CZY. The effects of water vapor and SO2 on the catalytic activity of 1.1 wt % Pt/3DOM CZY were also examined. It is concluded that the excellent catalytic acti...

Highly dispersed Pt nanoparticles supported on high-surface-area 3D ordered macroporous (3DOM) Ce0.6 Zr0.3 Y0.1 O2 (CZY) are synthesized via a bubbling cetyltrimethyl ammonium bromide/P123-assisted reduction route. The 1.1 wt% Pt/3DOM CZY catalyst shows supercatalytic activity for methane combustion, which is attributed to a higher oxygen adspecies amount, larger surface area, better low-temperature reducibility, and unique nanovoid-walled 3DOM structure.

We report on the design and synthesis of CFs@NiO-NSs and NiO-NSs core–shells by growing nickel oxide nanosheets (NiO-NSs) on carbon fibers (CFs), and test their applications as supercapacitors. We fabricate electrodes based upon the CFs@NiO-NSs core–shell and the NiO-NSs shell and measure their electrochemical performances. In comparison to the NiO-NSs electrode, the CFs@NiO-NSs electrode shows a more enhanced electrochemical performance with a high specific capacitance of 891.1 F g−1 at a current density of 1 A g−1, a good rate capability with 83.3% retention even at a high current density of 20 A g−1, and an excellent cycling stability by retaining 95% even after 5000 cycles. These results make the CFs@NiO-NSs a promising electrode material for high-performance supercapacitors.

We report a synthesis of NiCo2S4 nanosheet arrays with self-decorated nanoneedles on nickel foams by a facile and efficient two-step hydrothermal approach. We demonstrate that the morphologies of various three-dimensional nanostructures such as nanoneedle arrays, nanosheet arrays, and nanoneedle-decorated nanosheet arrays can be manipulated by tuning the amount of additive ammonium fluoride alone in the reaction. The unusual nanostructure of nanoneedles grown on the surface of NiCo2S4 nanosheet arrays shows a large electroactive surface area and superior electrochemical properties. The electrode made of the NiCo2S4 nanosheet arrays with self-decorated nanoneedles shows greatly improved electrochemical performances with an ultrahigh specific capacitance of 2617.6 F g−1 at a current density of 15 mA cm−2 and of 2051.0 F g−1 even at a current density of 30 mA cm−2. The electrode also exhibits an excellent cycling stability by retaining 93.2% of its original state after 5000 cycles, rendering the NiCo2S4 nanosheet arrays with self-decorated nanoneedles a potential electrode material for high-performance supercapacitors.

A series of Ag nanoparticles (NPs) supported on three-dimensionally ordered macroporous (3DOM) La0.6Sr0.4MnO3 (yAg/3DOM La0.6Sr0.4MnO3; y = 0, 1.57, 3.63, and 5.71 wt %) were successfully prepared with high surface areas (38.2–42.7 m2/g) by a facile novel reduction method using poly methacrylate colloidal crystal as template in a dimethoxytetraethylene glycol (DMOTEG) solution. Physicochemical properties of these materials were characterized by means of numerous techniques, and their catalytic activities were evaluated for the combustion of methane. It is shown that the yAg/3DOM La0.6Sr0.4MnO3 materials possessed unique nanovoid-like 3DOM architectures, and the Ag NPs were well dispersed on the inner walls of macropores. Among the La1–xSrxMnO3 (x = 0.2, 0.4, 0.6, 0.8) and yAg/3DOM La0.6Sr0.4MnO3 (y = 0, 1.57, 3.63, and 5.71 wt %) samples, 3.63 wt % Ag/3DOM La0.6Sr0.4MnO3 performed the best, giving T10%, T50%, and T90% (temperatures corresponding to methane conversion =10, 50, and 90%) of 361, 454, and 524...

Three-dimensionally macroporous perovskite-type oxides EuFeO 3 (EFO-3DOM, EFO-sucrose-1, EFO-sucrose-2, and EFO-sucrose-3, respectively) have been prepared using the polymethyl methacrylate-templating method in the absence or presence of sucrose. Physicochemical properties of the materials were characterized by means of a number of analytical techniques, and their catalytic activities were evaluated for the total oxidation of toluene. It is shown that all of the EFO samples were of single-phase orthorhombic crystal structure with a 3DOM architecture. The sucrose addition during the preparation process had a great effect on the surface area and porous structure of the final product. A clear correlation of surface area, surface oxygen species concentration, and low-temperature reducibility with the catalytic performance was observed. The EFO-sucrose-1 catalyst performed the best, giving the T 50% and T 90% of 312 and 347 °C at space velocity = 20,000 mL/(g h), respectively. The apparent activation energies of the 3DOM-structured EFO samples were in the range of 82–97 kJ/mol. It is concluded that the higher surface area and oxygen adspecies concentration and better low-temperature reducibility account for the good catalytic activity of EFO-sucrose-1.

Cylinder- and cake-like Cr 2 O 3 with a rhombohedral structure were fabricated using the hydrothermal and microemulsion methods, respectively. It is found that surface areas, surface Cr 6 + and oxygen adspecies concentrations, and low-temperature reducibility of cake-like Cr 2 O 3 were much higher or better than those of the bulk counterpart. The cake-like Cr 2 O 3 sample showed the best catalytic performance for toluene combustion, giving the T 50% and T 90% of 229 and 240 °C at SV = 20,000 mL/(g h), respectively. The excellent catalytic performance of cake-like Cr 2 O 3 was associated with its oxygen adspecies concentration and good low-temperature reducibility.

Strontium ferrite (SFO) hollow spheres with or without porous shells were fabricated via a novel one-pot hydrothermal route with the assistance of glucose and/or ethylenediamine. Physicochemical properties of the materials were characterized by means of a number of analytical techniques, and their catalytic performance was evaluated for the combustion of toluene. It is shown that the SFO samples possessed an orthorhombic structure and displayed a porous hollow spherical morphology with a surface area of 18–27 m 2 /g. The SFO sample (SFO-3) derived hydrothermally at 170 °C with a glucose/ethylenediamine volumetric ratio of 0.3/1.0 exhibited the highest surface area and oxygen adspecies concentration and the best low-temperature reducibility. Among the SFO samples, the SFO-3 sample showed the best catalytic activity for toluene combustion, and the T 10% , T 50% , and T 90% were ca. 145, 255, and 298 °C at a space velocity of 20,000 mL/(g h), respectively. It is concluded that the good catalytic performance of SFO-3 was associated with its surface oxygen species concentration and better low-temperature reducibility.

Porous LaFeO 3 (LFO) samples with surface areas of 15–26 m 2 /g and orthorhombic structures were prepared via a glucose-assisted hydrothermal route. Physicochemical properties of the materials were characterized by means of a number of techniques, and their catalytic activities were evaluated for toluene combustion. It is found that the sample (LFO-170) derived at a hydrothermal temperature of 170 °C possessed the highest surface area and surface oxygen concentration and the best low-temperature reducibility. Among the LFO samples, the LFO-170 sample showed the best performance for toluene combustion, giving the T 10% , T 50% , and T 90% of 180, 250, and 270 °C at space velocity=20,000 mL/(g h), respectively. The apparent activation energies of the LFO samples were 50–55 kJ/mol. We believe that the high surface area and surface oxygen concentration and good low-temperature reducibility were responsible for the good catalytic performance of the LFO-170 sample.

Fluoride-doped BiVO4 with the F/Bi molar ratios of 0, 0.09, 0.13, and 0.29 (denoted as BiVO4–F0, BiVO4–F0.09, BiVO4–F0.13, and BiVO4–F0.29, respectively) were synthesized using the hydrothermal strategy with the hydrothermally derived BiVO4 as the precursor and NH4F as the fluoride source. Physicochemical properties of the materials were characterized by means of a number of analytical techniques. Photocatalytic activities of the fluoride-doped BiVO4 samples were evaluated for the degradation of phenol under visible-light irradiation. It is shown that compared to the undoped BiVO4–F0 sample, the fluoride-doped BiVO4 samples retained the monoclinic structure, but possessed higher surface areas and oxygen adspecies concentration, better light-absorbing performance, and lower bandgap energies. Among the four samples, the porous spherical BiVO4–F0.29 sample exhibited the best photocatalytic activity for the degradation of phenol in the presence of a small amount of H2O2 under visible-light illumination. It is concluded that the higher surface area and oxygen adspecies concentration, stronger optical absorbance performance, and lower bandgap energy were responsible for the excellent photocatalytic performance of BiVO4–F0.29 for the photocatalytic degradation of phenol.

Three-dimensional (3D) macroporous perovskite-type oxides SrFeO 3− δ (i.e., SFO- x EG, x = 1, 3, and 6) with a cubic perovskite structure have been prepared using the citric acid-assisted poly(methyl methacrylate)-templating method in the presence of a certain amount (1, 3 or 6 mL) of ethylene glycol (EG). The physicochemical properties of the materials were characterized by means of numerous techniques and their catalytic activities were evaluated for toluene combustion. It is shown that the SFO-3EG sample possessed the best pore quality and highest surface area (ca. 34 m 2 /g). Most of the pores of SFO- x EG ( x = 1, 3, and 6) were ca. 72, 52, and 64 nm, respectively. There was a good relationship of surface area, oxygen adspecies concentration, and low-temperature reducibility with catalytic performance of the sample (i.e., SFO-3EG > SFO-6EG > SFO-1EG > SFO-bulk). The SFO-3EG catalyst performed the best, giving a T 50% of ca. 270 °C and a T 90% of ca. 310 °C at space velocity = 5000 mL/(g h). It is concluded that the good catalytic performance of SFO-3EG was associated with its large surface area, high oxygen adspecies concentration, and good low-temperature reducibility as well as the high-quality 3D macroporous structure.

Three-dimensionally ordered macroporous (3DOM) perovskite-type oxides EuFeO 3 (EFO-3DOM) and Eu 0.6 Sr 0.4 FeO 3 (ESFO-3DOM) were prepared by the citric acid-assisted polymethyl methacrylate-templating method. The physicochemical properties of the materials were characterized by means of numerous techniques. Catalytic activities of these porous samples were evaluated for the combustion of toluene. It is shown that the EFO-3DOM and ESFO-3DOM catalysts were of high-quality 3DOM architecture and single-phase orthorhombic crystal structure with a surface area of 16–31 m 2 /g. The sequence in surface oxygen species concentration and low-temperature reducibility decreased in terms of ESFO-3DOM > EFO-3DOM > EFO-bulk, in good agreement with the order in catalytic activity. The ESFO-3DOM catalyst exhibited the best performance, giving the T 10% , T 50% , and T 90% of 233, 278, and 305 °C at a space velocity of 20,000 mL/(g h), respectively. Apparent activation energies of the ESFO-3DOM, EFO-3DOM, and EFO-bulk catalysts were ca. 82, 96, and 104 kJ/mol, respectively. The excellent catalytic activity of ESFO-3DOM might be associated with its higher surface area and surface oxygen species concentration and better low-temperature reducibility as well as high-quality 3DOM structure.

Three-dimensionally ordered macroporous (3DOM) Eu0.6Sr0.4FeO3-supported cobalt oxide nanocatalysts (yCoOx/3DOM-ESFO; y wt% = 1, 3, 6, and 10) were prepared using the incipient wetness impregnation method. Physicochemical properties of the composite materials were characterized by means of numerous techniques, and their catalytic performance was evaluated for the combustion of toluene. It is shown that all of the samples displayed a well-defined 3DOM architecture with a surface area of 22–31 m2 g−1 and the loaded cobalt oxide nanoparticles with a diameter of 7–11 nm were well dispersed on the surface of the 3DOM-ESFO support. Among the yCoOx/3DOM-ESFO samples, the 3CoOx/3DOM-ESFO and 6CoOx/3DOM-ESFO ones possessed the highest oxygen adspecies concentration and the best reducibility at low temperature, and hence showing the best catalytic performance (the temperatures required for 50 and 90% toluene conversions were ca. 250 and 270 °C at a space velocity of 20,000 mL g–1 h–1, respectively) for toluene combustion. The apparent activation energies (ca. 72 kJ mol−1) of 3CoOx/3DOM-ESFO and 6CoOx/3DOM-ESFO were lower than that (81 kJ mol−1) of 3DOM-ESFO. It is concluded that the enhanced catalytic performance of 3CoOx/3DOM-ESFO and 6CoOx/3DOM-ESFO for toluene combustion was mainly related to their higher oxygen adspecies concentrations, stronger reducibility at low temperature, and better dispersion of cobalt oxide nanoparticles.

Three-dimensionally ordered macroporous (3DOM) and bulk Co3O4, Eu0.6Sr0.4FeO3 (ESFO), and 3 wt% Co3O4/Eu0.6Sr0.4FeO3 (3Co3O4/ESFO) were fabricated using the PMMA-templating (3DOM-Co3O4 and 3DOM-ESFO), citric acid-assisted hydrothermal (Co3O4-bulk and ESFO-bulk), and incipient wetness impregnation (3Co3O4/3DOM-ESFO and 3Co3O4/ESFO-bulk) methods, respectively. Physicochemical properties of these materials were characterized by means of various techniques, and their catalytic activities were evaluated for toluene combustion. Compared to the nonporous Co3O4 and ESFO samples, the 3DOM-Co3O4, 3DOM-ESFO, and 3Co3O4/3DOM-ESFO samples exhibited higher oxygen adspecies concentrations and better low-temperature reducibility. The 3Co3O4/3DOM-ESFO sample showed the best catalytic activity for toluene combustion, giving the T50% and T90% of 251 and 269 °C at 20,000 mL/(g h), respectively. The apparent activation energies of these samples were in the range of 72–88 kJ/mol. We believe that the higher oxygen adspecies concentration, better low-temperature reducibility, and synergistic action between Co3O4 and 3DOM-structured ESFO were responsible for the excellent catalytic performance of 3Co3O4/3DOM-ESFO.

The NiO samples (NiO-HMTA, NiO-HMTA-PEG, NiO-HMTA-PVP, and NiO-urea, respectively) with a surface area of 31 −66 m2/g and porous nanoflower- and nanourchin-like morphologies were prepared via the hydrothermal route with hexamethylenetetramine (HMTA) or urea as precipitator in the absence or presence of surfactant (poly(ethylene glycol) (PEG) or polyvinyl pyrrolidone (PVP)). It is shown that NiO-HMTA-PVP possessed the highest surface area and Oads concentration and the best reducibility. The NiO-HMTA-PVP catalyst performed the best (T50% = 253 °C and T90% = 266 °C). The excellent catalytic activity of NiO-HMTA-PVP was associated with its large surface area, high Oads concentration, and good reducibility.

The rod-like tetragonal α-MnO 2 , flower-like hexagonal ɛ-MnO 2 , and dumbbell-like tetragonal β-MnO 2 were prepared using the hydrothermal or water-bathing method under different conditions. It is shown that the α-MnO 2 , ɛ-MnO 2 , and β-MnO 2 catalysts possessed a surface area of ca. 53, 30, and 114 m 2 /g, respectively. The oxygen adspecies concentration and low-temperature reducibility decreased in the order of α-MnO 2 > ɛ-MnO 2 > β-MnO 2 , coinciding with the sequence of their catalytic activities for toluene combustion. The well-defined morphological MnO 2 catalysts performed much better than the bulk counterpart. At a space velocity of 20,000 mL/(g h), the temperature for 90% toluene conversion was 238, 229, and 241 °C over α-MnO 2 , ɛ-MnO 2 , and β-MnO 2 , respectively. The apparent activation energies of α-MnO 2 , ɛ-MnO 2 , and β-MnO 2 were in the range of 20–26 kJ/mol. It is concluded that higher oxygen adspecies concentrations and better low-temperature reducibility were responsible for the good catalytic performance of the α-MnO 2 , ɛ-MnO 2 , and β-MnO 2 materials.

Three-dimensionally ordered macroporous (3DOM) cubic perovskite-type oxides SrFeO 3− δ were prepared using the citrate acid-assisted poly(methyl methacrylate)-templating method in the presence of ethylene glycol, sucrose or l -lysine (denoted as SFO-0, SFO-Sucrose, and SFO-Lysine, respectively). It is found that the SrFeO 3− δ samples possessed a 3DOM architecture and were high in surface area (34–61 m 2 /g). The porous SrFeO 3− δ catalysts performed well in toluene combustion, with the SFO-0 sample exhibiting the highest catalytic activity ( T 50% = 292 °C and T 90% = 340 °C at 20,000 mL/(g h)). The catalytic activity of the samples showed a good relationship with surface area, oxygen adspecies concentration, and low-temperature reducibility, all decrease in the order of SFO-0 > SFO-Lysine > SFO-Sucrose ≫ SFO-bulk. It is deduced that the good catalytic performance of the porous SrFeO 3− δ materials is due to the good low-temperature reducibility, large surface area, and high oxygen adspecies concentration.

Nanosized rod-like, wire-like, and tubular α-MnO(2) and flower-like spherical Mn(2)O(3) have been prepared via the hydrothermal method and the CCl(4) solution method, respectively. The physicochemical properties of the materials were characterized using numerous analytical techniques. The catalytic activities of the catalysts were evaluated for toluene oxidation. It is shown that α-MnO(2) nanorods, nanowires, and nanotubes with a surface area of 45-83 m(2)/g were tetragonal in crystal structure, whereas flower-like spherical Mn(2)O(3) with a surface area of 162 m(2)/g was of cubic crystal structure. There were the presence of surface Mn ions in multiple oxidation states (e.g., Mn(3+), Mn(4+), or even Mn(2+)) and the formation of surface oxygen vacancies. The oxygen adspecies concentration and low-temperature reducibility decreased in the order of rod-like α-MnO(2) > tube-like α-MnO(2) > flower-like Mn(2)O(3) > wire-like α-MnO(2), in good agreement with the sequence of the catalytic performance of these samples. The best-performing rod-like α-MnO(2) catalyst could effectively catalyze the total oxidation of toluene at lower temperatures (T(50%) = 210 °C and T(90%) = 225 °C at space velocity = 20,000 mL/(g h)). It is concluded that the excellent catalytic performance of α-MnO(2) nanorods might be associated with the high oxygen adspecies concentration and good low-temperature reducibility. We are sure that such one-dimensional well-defined morphological manganese oxides are promising materials for the catalytic elimination of air pollutants.

Three-dimensionally ordered macroporous (3DOM) europium oxide and samarium oxide with mesoporous walls and cubic crystal structures have been successfully fabricated with polymethyl methacrylate (PMMA) as hard template and F127, sucrose, and l -lysine as surfactant. The as-fabricated rare earth oxides were characterized by means of X-ray diffraction, thermogravimetric analysis, differential scanning calorimetric analysis, Fourier-transform infrared spectroscopy, scanning electron microscope, transmission electron microscopy, selected-area electron diffraction, nitrogen adsorption–desorption, ultraviolet–visible diffuse reflectance spectroscopy, and photoluminescence spectroscopy. It is shown that the as-fabricated Eu 2 O 3 and Sm 2 O 3 samples displayed 3DOM architectures with polycrystalline wormhole-like mesoporous walls. The nature of surfactant and solvent and calcination parameter had important effects on the pore structure and surface area of the final product. The introduction of surfactant and the carbonization of sucrose or l -lysine favored the enhancement in surface area of the 3DOM-structured materials, with the 3DOM Eu 2 O 3 and Sm 2 O 3 samples derived in the presence of sucrose possessing the highest surface area of 36.8 and 32.6 m 2 g −1 , respectively. The 3DOM Eu 2 O 3 and Sm 2 O 3 samples showed much better UV-light absorption capacity than their bulk counterparts. The PL study revealed that the luminescent properties could be modified by tailoring the pore structure of Eu 2 O 3 and Sm 2 O 3 . The unique physical properties associated with the generation of 3DOM skeletons and wormhole-like mesoporous walls make such materials useful for the applications in optics and heterogeneous catalysis.

Bismuth vanadates with multiple morphologies and/or porous structures were prepared using the alcoho-hydrothermal strategy with bismuth nitrate and ammonium metavanadate as metal source, NaOH as pH adjustor, ethanol and ethylene glycol as solvent, and/or dodecylamine (DA), oleylamine (OL) or oleic acid (OA) as surfactant. The materials were characterized by means of the XRD, Raman, TGA/DSC, FT-IR, BET, SEM, TEM, XPS, and UV–vis techniques. The photocatalytic performance of the as-obtained samples was evaluated for the degradation of phenol in the presence of a small amount of H 2 O 2 under visible-light irradiation, and the effect of phenol concentration on the photocatalytic activity was also examined. It is found that the surfactant and pH value had a significant influence on the particle morphology and even the crystalline structure of the product. Porous olive-like monoclinic BiVO 4 samples could be prepared with DA, OL or OA as surfactant at pH = 1.5 or 3.0 and alcoho-hydrothermal temperature = 100 °C. With DA as surfactant at an alcoho-hydrothermal temperature of 100 °C, short-rod-like monoclinic BiVO 4 and porous sheet-layered spherical orthorhombic Bi 4 V 2 O 11 were obtained when the pH value of the precursor solution was raised to 7.0 and 11.0, respectively. Among the BiVO 4 samples, the porous olive-like one with a surface area of 12.7 m 2 /g exhibited the best visible-light-driven photocatalytic performance for phenol degradation. It is concluded that the excellent photocatalytic activity of the porous olive-like BiVO 4 sample was associated with its higher surface area and surface oxygen vacancy density, porous structure, lower bandgap energy, and unique morphology.

Three-dimensionally ordered macroporous (3DOM) ceria with mesoporous walls and cubic crystal structures were prepared with polymethyl methacrylate (PMMA) as a hard template and triblock copolymer Pluronic F127 (EO 106 PO 70 EO 106 ), cetyltrimethylammonium bromide (CTAB), or poly(ethylene glycol) (PEG) as a soft template. Citric acid was used as a complexing agent and cerium nitrate was used as a metal precursor. The 3DOM CeO 2 samples were characterized by numerous analytical techniques. The as-fabricated CeO 2 samples had a 3DOM architecture with polycrystalline wormhole-like mesoporous walls. The nature of the soft template had an important effect on the pore structure and the surface area of the final product. The surface areas of the F127-, CTAB-, and PEG-derived 3DOM CeO 2 samples (denoted CeO 2 -F127, CeO 2 -CTAB, and CeO 2 -PEG, respectively) were ca. 60.5, 60.2, and 51.8 m 2 /g, respectively. The low-temperature reducibility of the 3DOM-structured CeO 2 samples was much better than that of the bulk counterpart and the low-temperature reducibility of the three 3DOM ceria samples increased according to: CeO 2 -PEG 2 -CTAB 2 -F127, which coincided with the surface oxygen vacancy density sequence. The improved physicochemical properties associated with the formation of the 3DOM skeleton with wormhole-like mesoporous walls may be useful for applications such as CeO 2 materials in heterogeneous catalysis.

Monoclinic BiVO4 with multiple morphologies were fabricated using the alcoho-hydrothermal strategy with bismuth nitrate and ammonium metavanadate as inorganic sources, NaOH for pH adjustment, and the triblock copolymer P123 as a surfactant. The materials were characterized by X-ray diffraction, nitrogen adsorption-desorption, scanning electron microscopy, X-ray photoelectron spectroscopy, and ultraviolet-visible diffuse reflectance spectroscopy. The photocatalytic performance of the BiVO4 samples was evaluated for the degradation of methyl orange (MO) under visible-light irradiation condition. The results showed that the surfactant and pH had a significant influence on the particle morphology of the BiVO4 product. Porous spherical, flower-like, and sheet-like BiVO4 were fabricated at an alcoho-hydrothermal temperature of 180 °C and at a pH of 2, 7, or 10, respectively, whereas rod-like BiVO4 was obtained in the presence of P123 at an alcoho-hydrothermal temperature of 180 °C and at a pH of 2. The difference in BiVO4 particle morphology led to differences in surface area, surface oxygen vacancy density, and (040) crystal plane exposure. Among the four BiVO4 samples, the rod-like sample had the highest surface area, surface oxygen vacancy density, and (040) crystal plane exposure, and the lowest bandgap energy resulting in it having the best photocatalytic activity for MO photodegradation. It can be concluded that a morphological effect is responsible for the photocatalytic performance and the rod-like morphology seems to favor an enhancement in the photocatalytic performance of the BiVO4 material.