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Soap-free poly(methyl methacrylate-ethyl acrylate-methacrylic acid) latex particles with narrow size distribution were synthesized by seeded emulsion polymerization, and the porous particles were created by a stepwise alkali/acid treatment method. Effects of acid treatment conditions on the particle morphology were investigated. Results show that one to three pores were formed inside most of particles after post-treatment. At pH 7.0, when the treatment temperature was lower than 70°C, the size of particles and the volume of pores remained almost unchanged, and these two values increased significantly when the temperature was higher than 70°C. Both the particle size and the pore volume decreased with the increase in initial pH value and treatment time in the acid treatment. As the pH was below 4.0 and the treatment time was longer than 180 min, the particles shrunk in size.

To repair bone defects, an important approach is to fabricate tissue engineering scaffolds as substitutions to replace auto-/allologous bones. Currently, processing a biomaterial into three-dimensional porous scaffolds and incorporating the calcium phosphate (Ca–P) nanoparticles into scaffolds profile two main characteristics of bone tissue engineering scaffolds. Based on this fact, in this paper we describe the design principles of the Ca–P nanoparticle-based and porous bone tissue engineering scaffolds. Then we summarize a variety of the Ca–P nanoparticle-based scaffolds, including discussion of the integration of the Ca–P nanoparticles with ceramics and polymers, followed by introduction of safety of the Ca–P nanoparticles in scaffolds.

Ag pillared interlayered clays (Ag-PILCs) were synthesized through a novel method, in which Ag nanoparticles were formed in montmorillonite interlayers. In this method, silver ions were first exchanged into montmorillonite interlayers, and then reduced into Ag nanoparticles by trisodium citrate at 100°C in aqueous solutions. The synthesized Ag@montmorillonite nanocomposite was characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM), and its surface area was evaluated by using Brunauer–Emmet–Teller (BET) method. Compared to traditional PILCs synthesized through ion exchange method, the formed Ag-PILCs had better thermal stability and stronger structure because their pillars are nanoparticles. Furthermore, this method introduces a possibility to control the size of the pillars and thus the pore size of the PILCs, due to that the nanoparticle pillars can be modified on their forms and diameters in the synthesizing process. Also, it was found that the intercalating Ag nanoparticle pillars were formed at restricted pH values and silver ion concentrations.

Porous NiCo₂S₄ networks have been successfully synthesized by a facile one-pot solvothermal method without the use of any surfactant or template. Crystal structure, morphology, composition and surface area of the as-synthesized samples were characterized by X-ray diffraction, field-emission scanning electron microscopy, X-ray photoelectron spectroscopy and Brunauer–Emmet–Teller techniques. Owing to their porous nature and small crystalline size, the as-prepared NiCo₂S₄ networks based supercapacitor electrodes showed a high specific capacitance of 1250F$\cdot$g${}^{-1}$ at 1A$\cdot$g${}^{-1}$, and excellent cycling stability with the retention capacity of 70.3% after 5000 cycles in the KOH aqueous solution electrolyte.

Here, the lamellar-shaped Bi₂S₃ grown on a porous TiO₂ monolith was obtained by a two-step method including a sol–gel route and hydrothermal treatment. The photocatalytic activity of the as-synthesized Bi₂S₃/TiO₂ composites was evaluated for photodegradation of methylene blue (MB) dye in aqueous solution under the visible-light irradiation. Based on our experimental results, 5% (molar ratio of Bi₂S₃ to TiO${}_2)$ Bi₂S₃/TiO₂ photocatalysts exhibited a maximum photodegradation rate of MB up to 96.9% under visible-light irradiation for 120 min. Our findings indicated that the lamellar-shaped Bi₂S₃ can extend the light absorption up to visible areas, and porous TiO₂ can provide enhanced specific surface area and more mass transfer pathway to enhance the photodegradation efficiency. Furthermore, porous TiO₂ can accept the electrons from the Bi₂S₃ conduction band due to the relatively positive electrode potential to impede the photoproduced electron and hole combination to result in advanced photocatalytic performance.

In this report, the porous Fe₃O₄/C nanocomposites were successfully synthesized by using ferrocene as raw material and dilute nitric acid as solvent via extremely convenient and low-cost one-step calcining method. The formation of porous structure resulted from the aggregation and assembly of numerous nanoparticles. The experimental results show that the crystallinities, morphologies and electrochemical performance of samples were affected by the calcining temperature and carbon content. As an anode for lithium-ion batteries (LIBs), the Fe₃O₄/C nanocomposites obtained at calcination temperature of 500^∘C (Fe₃O₄/C-a500) exhibited remarkable initial specific discharge capacity of 1418mAh g${}^{-1}$ and a reversible capacity retention of 721mAhg${}^{-1}$ after 100 cycles at the current density of 100mAg${}^{-1}$. The excellent properties can be attributed to the high theoretical capacity of Fe₃O₄, the high conductivity of carbon and especially the porous structure, which offered more sites for the storage and insertion of Li ions. Even at the current density of 1000mAhg${}^{-1}$, the reversible capacity of Fe₃O₄/C-a500 can be up to 291mAhg${}^{-1}$, indicating the prepared typical nanocomposite presented excellent electrochemical performances and lithium storage capacity, which may be a promising candidate as the anode material for LIBs.

In this study, we have successfully synthesized porous CoO–Co@RGO composites using GO and Co-based metal-organic frameworks (MOFs) as precursors. Due to particular structures and advantageous characteristics, the synthesized porous CoO–Co@RGO composites exhibit outstanding electromagnetic (EM) wave absorbing properties with a filler loading of 10wt.% in wax matrix. The maximum reflection loss (RL) of the prepared porous CoO–Co@RGO was $-34.22$dB with 2.1mm thickness, and the effective absorption bandwidth as wide as 6.24GHz (11.76–18GHz), which covers the full Ku-band. Remarkably, the achieved all values ofRL were under $-10$dB with 1.0–5.0mm thickness, the corresponding to bandwidth range can be tuned to 13.84GHz (4.16–18GHz). The superior absorbing performance is attributed to suitable magnetic loss, high dielectric loss and large attenuation mainly caused by conduction loss and polarization relaxation.

The passive direct methanol fuel cell (DMFC) is a promising candidate power source for portable applications but has to deal with many technical challenges before practical use. This study presents a preliminary investigation on the use of a woven carbon fiber fabric (WCFF) for constructing a gradient porous structure based on the traditional design. The WCFF, carbon paper and carbon-black micro porous layer (MPL) combine into a carbon-based assembly which acts as a mass-transfer-controlling medium at the anode of a passive DMFC. Results show that this novel setup is able to significantly improve the cell performance and facilitate high-concentration operation. A maximum power density of 16.4 mWcm^-2 is obtained when two layers of the WCFF are used at a methanol concentration of 8M. This work provides an effective method for using concentrated methanol with no need for major change of the fuel cell configuration.

With the continuous depletion of fossil energy, emerging energy storage equipment based on supercapacitors has been developed rapidly due to their high energy/power density, low cost, long cycle lives and environmental friendliness. The electrode materials of supercapacitors with high specific surface area, porous structure and excellent electrochemical activity are first important and need to be carefully designed. Here, we propose a three-dimensional chitosan/graphene (CS-rGO) aerogel with vertical alignment as the electrodes for the construction of a symmetrical all-solid-state supercapacitor. The unique structures of the aerogel with low density and light mass, direct channel with low tortuosity, high electronic conductivity favor its high volume capacitance of 184.6 mF cm${}^{-3}$ at a current density of 2 mA cm${}^{-3}$, high energy density of 32 W h kg${}^{-1}$ at power density of 1000 W kg${}^{-1}$ and 89.8% retention rate of the volume capacitance after 5000 cycles at 10 mA cm${}^{-3}$. This demonstrates the potential application of CS-rGO aerogel in symmetric supercapacitors (SSCs) for energy storage and conversion.

As a potential nonmetal activator of peroxymonosulfate (PMS), $g$-C₃N₄ becomes a hot material owing to its superior chemical and physical properties. Nevertheless, pristine $g$-C₃N₄ is unsatisfactory for PMS activation because of its limited photo-generated charge separation and low specific surface area. Herein, a porous sulfur-doped $g$-C₃N₄ (S-doped $g$-C₃N${}_4)$ has been prepared through a one-step calcination route without a template. The in-situ doping of sulfur element and the formation of porous morphology have been confirmed via various characterization methods. The catalytic activity of porous S-doped $g$-C₃N₄ is approximately 6.2-fold higher than that of the pristine $g$-C₃N₄ on rhodamine B (RhB) decomposition in aid of the photo-assisted PMS activation. The superior catalytic activity and high stability of the porous S-doped $g$-C₃N₄ catalyst in a wide pH range are attributed to its higher specific surface area, enriched active sites, efficient photo-induced charge separation, and increased visible-light utilization. Meantime, a synergistic effect between the PMS activation process and the photocatalytic process is conducive to produce abundant radicals for the RhB degradation. This study offers new insight into further developing highly efficient nonmetal heterogeneous catalysts for wastewater treatment.

Graphene-oxide (GO) is one of the most commonly used carbon nanomaterials in advanced applications such as microwave absorption and EMI shielding, due to various advantages such as ease of synthesis and exfoliation, effective doping capability, and superior composite compatibility. In this study, we used the modified Hummer’s method to synthesize GO by exfoliating graphite powder, and a simple hydrothermal approach was employed for elemental doping and GO reduction. As nitrogen–sulfur (N, S) dual-doping precursors, thiourea and l-cysteine amino acids were utilized. The structural features and microporous network structure of GO aerogel foams were investigated. The microwave absorption capabilities of polyethersulfone-based nanocomposite films incorporating the as-produced nitrogen–sulfur enrich reduced GO (NS-rGO) are also explored. According to the physicochemical characterization, the existence of remarkable structural defects with a porous three-dimensional (3D) network was discovered due to heteroatom insertion and hydrothermal doping. Additionally, the dual-doped sample exhibited high Nitrogen and sulfur content of 8.93% and 13.19%, respectively. While NS-rGO possesses a higher conductivity of 174.7$\mu$S compared to 12.65$\mu$S for GO. The nanocomposites filled with NS-rGO foams demonstrated a high shielding efficiency (SE) of 45dB in the X-band with a filler loading of 0.5wt.%. This high SE arises from dopant heteroatoms and the heterogeneous interface, which induce interface polarization, thereby increasing microwave absorption and dielectric constant. It also results from multi-level reflections caused by the 3D porous structures. These findings offer valuable insights into the functionalization of carbon nanostructures and the development of 3D networks in GO-based functional materials, providing further guidance for engineering high-performance electromagnetic interference shielding materials.