Abstracts:Rapid thermal swing adsorption (RTSA) using hollow fiber sorbents (HFSs) is an emerging separation process that enables significant energy savings. Herein, we propose a self-regenerative RTSA process based on multi-modules of zeolite-13X-impregnated HFSs for energy-efficient H2O removal in various chemical processes. The proposed dehumidification process consumes almost 82% lower energy than the conventional adsorption counterpart for H2O removal because it uses a combination of high heat transfer efficiency and self-regeneration. The steam recovered from the desorption process can be combined with the thermal fluid for H2O desorption from the HFSs, which is referred to as the self-regenerative RTSA process. In addition, the residual sensible heat emitted from the desorption process can be internally integrated into the heating process, which reduces both the sensible heat of the HFSs and desorption heat of H2O. Consequently, the energy evaluation revealed that the newly proposed self-regenerative RTSA process required a total energy of ca. 0.68 GJ t-H2O-1 for H2O adsorption with a heat integration efficiency of 80%. The current work successfully demonstrates an extended application of the RTSA process for dehumidification.

Abstracts:The utilization and development of nuclear energy has resulted in the discharge of uranium-containing wastewater. Layer double hydroxides (LDHs) and oxides (LDOs) were reported for efficient extracting U(VI) from wastewater. In this work, nickel–cobalt layered double oxide (Ni-Co LDO-X, X represents the calcination temperature) with excellent electrostatic attraction and complexation was synthesized via calcination of nickel–cobalt layered double hydroxide (Ni-Co LDH) under air atmosphere for extracting U(VI) comparing to Ni-Co LDH. Scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and zeta potential analysis were conducted to characterize the Ni-Co LDO-X. Batch adsorption experiments were carried out to investigate the U(VI) extraction properties. The U(VI) adsorption capacity on Ni-Co LDO-500 increased over 3 times compared to that of Ni-Co LDH. The process of uranium removed by Ni-Co LDO-500 conforms to the Langmuir model, the calculated maximum adsorption capacity is 707.91 mg/g. The results suggested that the excellent U(VI) adsorption ability on Ni-Co LDO-500 mainly dominated by the memory effect, electrostatic interaction, and complexation on the outer-sphere surface. Ni-Co LDO-500 has excellent regeneration ability in five adsorption/desorption experiments. The Ni-Co LDO-500 had favorable ability in removing uranium in actual wastewater with the residual concentration being lower than 0.05 mg/L. The above results highlight that the Ni-Co LDO-500 is promising to be used for the decontamination of uranium in actual uranium-containing wastewater.

Abstracts:This study initially developed highly efficient self-healing materials with cerium(III) triflate [Ce(SO3CF3)3] as the metal center and phloretin as the ligand to synthesize a self-healable polyurethane elastomer with excellent self-healable and mechanical properties. Nuclear magnetic resonance data from experimental research on the self-healing mechanism indicated that Ce(SO3CF3)3 and phloretin could effectively form coordination bonds. Then, the hydroxyl group (−OH) on the para position of the phloretin reacted with the isocyanate group in the polyurethane prepolymer to form coordination-bond-facilitated self-healable polyurethane elastomers. An optimal sample (PUPC-2) with high tensile strength (5.17 Mpa) and high stretchability (1,415.7%), ideal toughness (35.08 MJ m−3), and remarkable healing efficiency (near to 100% healed after 48 h at room temperature) was obtained. In addition, the PUPC sample also exhibited good thermoplasticity, which means that the self-healable polyurethane elastomer can be recycled. These excellent performances ensure that the self-healable thermoplastic polyurethane elastomers have a wide range of practical applications. Therefore, a flexible conductive electrode with a self-healable capacity was obtained by compositing the PUPC-2 sample with flexible graphene-based conductive paper, which demonstrated good potential for application in the field of wearable devices and flexible electronics.

Abstracts:The solar-driven photoelectrocatalytic oxidation of urea is an efficient and costly way to produce hydrogen and purify wastewater synergistically. However, it is still a big challenge facing to the semiconductor-catalyst photoanode with high utilization of sunlight. Herein, we report a series of La-Ni-based Ruddlesden-Popper phases perovskite materials (Lan+1NinO3n+1, n = 1, 2 and 3) for photoelectrocatalytic oxidations of urea. Such La-Ni -based perovskite materials act simultaneously as a light-harvesting semiconductor and as the electrocatalyst for urea oxidation and all of Lan+1NinO3n+1 catalysts display a strong near-infrared (NIR) light absorption (≥ 800 nm). The La4Ni3O10 catalyst exhibits the best activity towards urea oxidation reaction (UOR) with an applied potential of 1.54 V vs. RHE at 1 mA cm-2, compared to that of 1.64 V and 1.56 V vs. RHE for La2NiO4 and La3Ni2O7, respectively, and 44.7 μmol cm-2h-1 of N2 generation rate under NIR light irradiation at the potential of 1.62 V vs. RHE, which is 2.5 times and 1.8 times of that for La2NiO4 and La3Ni2O7, respectively. The unique structure of La4Ni3O10 accelerates the separation and transport of electrons and holes, which is beneficial for the diffusion and adsorption of urea molecules in photoanode.

Abstracts:Bone regeneration following the removal of tumor tissues remains a major clinical challenge for the treatment of bone defects, in which materials with combinatory bone repair and osteolytic metastasis therapy is considered as a promising solution. Herein, a highly strong delignified wood/regenerated silk fibroin (RSF) hydrogel scaffold integrated with black phosphorus quantum dots (BPQDs) encapsulated by poly (lactic-co-glycolic acid) (PLGA) was engineered to realize efficient mechanical supporting, bone regeneration, and tumor therapy. Following delignification, the white wood (WW) scaffold significantly improved the mechanical properties of RSF composite hydrogel, with the elastic modulus in the L-direction and R-direction of 300 MPa and 3.3 MPa, and compression modulus in the L-direction of 9.3 MPa. Moreover, the WW/RSF hydrogel scaffold with BPQD/PLGA nanospheres effectively promoted the proliferation, migration, and osteogenic differentiation of bone mesenchymal stem cells and enhanced osteogenesis in vivo. Compared with the vertical implantation method, better bone regeneration was observed in parallel implantation system parallel to bone shaft. Importantly, the BPQDs in the hydrogel scaffolds could inhibit osteoclast differentiation and exhibit photothermal effects against metastatic tumor in the spine. Our data provide promising evidence for the potential therapeutic application on bone regeneration and ablation of bone metastasis.

Abstracts:Mesoporous bioactive glass (MBG) was one of the most promising bone regenerative materials for its well-acknowledged bioactivity, biodegradability, and osteoinductivity, as well as its potential for drug delivery. However, it remained a challenge to fabricate MBG scaffold with precisely controllable macro-structure and robust mechanical strength meanwhile to maintain uncompromised composition and mesoporosity. Herein, a fabricating route incorporating self-assembly and 3D printing (SAP) via acryloylating F127 (mesoporous template) was proposed and successfully realized directly printing MBG sol into hierarchical macro-/mesoporous SAP-MBG scaffold with compact and integral structure. Compared to traditional polyurethane (PU) templated MBG scaffold, SAP-MBG scaffold exhibited significantly enhanced mechanical strength meanwhile maintained non-composite component and mesoporous structure. SAP-MBG presented improved macropore interconnectivity and faster calcium dissolution, resulting in superior cellular penetration, in vitro osteogenic performances and in vivo bone regenerative efficacy in a critical-size rat cranial defect model. The SAP fabricating route represented an available approach to overcome the drawbacks of conventional manufacturing methods and realized individualized manufacturing of MBG scaffold. The synthetic design of this study might be extended to the fabricating process improvement of other mesoporous inorganic materials and shed light on future clinical translation of MBG scaffold in bone regeneration.

Abstracts:Electromagnetic wave absorbers with low infrared emissivity and excellent thermal insulation properties are attractive for multi-spectrum bands compatibility applications, but simultaneously meeting these requirements remains a great challenge. In this work, reduced graphene oxide/copper sulfide/stearic acid (rGO/[email protected]) aerogels loaded with phase change materials were prepared by facile solvothermal and freeze-drying technique. Due to the existence of CuS nanoparticles, the multiple reflection and scattering of incident electromagnetic waves are enhanced, so the microwave absorption performance is improved. As a result, the reflection loss (RL) of the sample reach −52.4 dB with an effective absorption bandwidth of 5.75 GHz at 2 mm. It has certain infrared stealth function at critical moment, compared with rGO, the infrared emissivity decreased from 0.89 to 0.59. And the phase change material (stearic acid) has a large latent heat of phase change, which is available to improve the thermal insulation performance of the material. When the detection angle θ is 0°, the maximum radar cross-section (RCS) reduction value of the sample reaches 23.85 dB m2. This work provides directions for designing light-weight absorbers with low infrared emissivity and thermal insulation performance for dual-spectrum bands compatibility.

Abstracts:Single atom catalysts have been shown highly efficient in catalyzing electrochemical CO2 reduction, but their large-scale synthesis and stable operation under high current densities are still rare. Herein a simple but robust template method was developed for gram-scale synthesis of single-atom Ni-N-C catalysts, exploiting the natural abundant and low-cost guar gum. Benefiting from its under-coordinated Ni-N3 configuration to afford high catalytic activity and hierarchical porosity to promote mass/charge transfer, the as-fabricated Ni-N/PC catalyst achieved a low overpotential of 290 mV at 100 mA cm−2, a near-unity faradaic efficiency in a wide potential range from −0.3 V to −0.8 V, as well as a stable operation for >70 h in a membrane electrode assembly with an extraordinary total energy efficiency of 41.0%. By mass-producing a highly potent single-atom electrocatalyst and demonstrating its stable operation in industrial-relevant conditions, this study paves the way for fulfilling the carbon neutral goal through the carbon-negative CO2RR process.

Abstracts:Antimony anodes for potassium-ion batteries (PIBs) have garnered considerable scholarly interest owing to their high theoretical specific capacity and low operation potential for alloying with potassium. However, the large volume expansion during alloying in Sb anodes results in rapid capacity fading. Thus, in this study, we proposed a simple, one-step, cost-effective carbothermal reduction method to synthesize a nanostructured Sb encapsulated in an N-doped porous carbon framework ([email protected]). The optimized [email protected] electrode, which was obtained using a Sb2O3:polyvinylpyrrolidone (PVP) molar ratio of 1:3, offered a high reversible capacity of 587.7 mAh g−1 at 100 mA g−1 over 50 cycles, 492 mAh g−1 at 200 mA g−1 over 100 cycles, and 360.8 mAh g−1 at 800 mA g−1 with a capacity retention of 75.7% over 500 cycles. Even at a high specific current of 4000 mA g−1, the electrode maintained a high reversible capacity of 385 mAh g−1, implying adequate rate capability. In addition, a full cell composed of [email protected] anode and KFe[Fe(CN)6⋅xH2O] cathode exhibited excellent cycling stability by showing an exceptional reversible capacity of 432.5 mAh g−1, corresponding to a high capacity retention of 98% over 150 cycles. These excellent results were primarily attributed to the successful encapsulation of nanostructured Sb nanoparticles in the NPC, as well as the formation of a KF-rich solid electrolyte interphase film on the electrode surface. Furthermore, the simulation result based on density functional theory (DFT) revealed that N-doping in the porous carbon framework enhanced the electrical conductivity and Sb−K binding.

Abstracts:Fabrication of self-healing elastomers with high strength and real-time (<30 s) self-healing capability is still a huge challenge. It is well documented that biological tissues with hierarchically anisotropic structures possess excellent self-healing and mechanical properties. Self-healing elastomer with similar hierarchically anisotropic structures as biological tissues has, however, not been reported yet. Herein, we highlight a facile strategy to fabricate self-healing elastomers with hierarchically anisotropic structures similar to tendons and ligaments by drying precursor hydrogels under fixed strains. Elastomers obtained by drying at 200% strain exhibit a high strength (8.4 MPa) and ultrafast self-healing ability (86% recovery after 10 s) under ambient conditions. Besides, elastomers with a surface CNT coating layer can be easily prepared by directly spraying the CNT suspension onto the surface of precursor hydrogel before drying under strain. Benefiting from the hierarchical structure of the surface CNT layer, the elastomer can be used as a sensor to detect minute human motions. This study provides a novel strategy for fabricating hierarchically anisotropic self-healing elastomers and simultaneously achieving high strength and real-time self-healing ability.