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A series of MXene/MnCo2O4.5 nanocomposites was successfully prepared by hydrothermal, ice crystal template and physical blend methods, respectively. Various characterizations indicated that hydrothermal method could successfully loaded MnCo2O4.5 nanoparticles on the surface of MXene nanosheets to obtain MMC-W nanocomposites with 3D flower-like structure, which could give MMC-W large specific surface area. The HTD temperature and decomposition heat of AP with adding 2.0 wt% MMC-W could significantly decrease to 304.7 °C and increase to 1310.9 J g-1, respectively. The lowest decomposition temperature (286.1 °C) and the highest heat release (1427.6 J g-1) of AP could be obtained by adding 8.0 wt% and 4.0 wt% of MMC-W, respectively. Moreover, MMC-W (2.0 wt%) could also significantly reduce the Ea of pure AP by 118.3 kJ mol-1 and increase the k value for AP by 11.2 times. The excellent catalytic performance of MMC-W was owing to the synergistic effect of nano-sized MnCo2O4.5 and MXene nanosheets. Owing to its high catalytic activity, MMC-W would be used as an excellent catalyst for ameliorating AP decomposition and supply an idea for the preparation of novel metal oxide nanoparticles.

Summary As the activation of N2 molecules is generally regarded as the bottleneck in N2 reduction, it is of significant importance to develop promising strategies to efficiently activate N2 molecules. Herein, we discovered an innovative approach to activate N2 molecules via hydrogen-bond interaction in N2 photofixation. Porous Cu with surface modification of S atoms (3%-S/Cu) exhibited remarkable catalytic activity and stability in N2 photofixation. Further mechanistic studies revealed that surface S atoms directly participated in the catalytic process by accepting and donating H atoms. In addition, the forming S–H bond significantly promoted the activation of N2 molecules via hydrogen-bond interaction, contributing to the enhanced catalytic activity.

As a radioactive heavy metal element with a long half-life, uranium causes environmental pollution when it enters the surrounding soil. This study analyzed the changes about soil enzyme activity, non-targeted metabolomics, microbial community structure and function microbial community structure and function to assess the differences in the effects of uranium stress on rhizosphere and non-rhizosphere soil. Results showed that uranium stress significantly inhibited the activities of urease and sucrase in rhizosphere and non-rhizosphere, which had less effect on rhizosphere. Compare to the non-rhizosphere soil, the uranium stress induced the production of gibberellin A1, to promoted several metabolic pathways, such as nitrogen and PTS (Phosphotransferase system) metabolic in rhizosphere soil. The species and abundance of Aspergillus, Acidobacter, and Synechococcus in both rhizosphere and non-rhizosphere soil were decreased by uranium stress. However, the microorganisms in rhizosphere soil were less inhibited according to the soil metabolism and microbial network map analysis. Furthermore, the Chujaibacter in rhizosphere soil under uranium stress was found significantly positively correlated with lipid and organic oxygen compounds. Overall, the results indicated that ryegrass roots significantly alleviated the effects of uranium stress on soil microbial activity and population abundances, thus playing a protective role. The study also provided a theoretical basis for in-depth understanding of the biological effects, prevention and control mechanisms of uranium-contaminated soil.

Microbial remediation of heavy metals in soil has been widely studied. However, bioremediation efficiency is limited in practical applications because of nutritional deficiency, low efficiency, and competition with indigenous microorganisms. Herein, we prepared a biochar-based microbial agent (BMA) by immobilizing the microbial agent (MA, containing Bacillus subtilis, Bacillus cereus, and Citrobacter sp.) on biochar for the remediation of U and Cd in soil. The results showed that BMA increased soil organic matter, cation exchange capacity, and fluorescein diacetate hydrolysis activity and dehydrogenase activity by 58.7%, 38.2%, 42.9%, and 51.1%. The availability of U and Cd were significantly decreased by 67.4% and 54.2% in BMA amended soil, thereby reducing their accumulation in vegetables. BMA greatly promoted vegetable growth. Additionally, BMA significantly altered the structure and function of rhizosphere soil microbial communities. Coincidently, more abundant ecologically beneficial bacteria like Nitrospira, Nitrosomonas, Lysobacter, and Bacillus were observed, whereas plant pathogenic fungi like Fusarium and Alternaria reduced in BMA amended soil. The network analysis revealed that BMA amendment increased the tightness and complexity of microbial communities. Importantly, the compatibility of niches and microbial species within co-occurrence network was enhanced after BMA addition. These findings provide a promising strategy for suppressing heavy metal accumulation in vegetables and promoting their growth.

This paper described one-step method to preparing supercapacitors by using natural ganoderma lucidum spores, whose hollow cage structure could facilitate the transmission and storage of electrons. We have investigated the effects of carbonized temperature and carbonized gas on the electrochemical properties of spores. After carbonizing the spore material under flowing ammonia, the nitrogen doping content of it was 8.86%. The specific capacitance of the prepared electrode was 187.3 F/g (at 1 A/g). After 10,000 charge-discharge cycles, the sample remained 93.3% of its capacity. In addition, after being irradiated by γ ray (50 kGy), the carbonized sample remained 100.7 F/g (at 1 A/g) of specific capacitance.

Ion adsorption by fungal hyphae (FH)-supported adsorbents represents a promising approach to remove the radioactive ion in water, whereas the existing organics in wastewater reduce the adsorption efficiency. Herein, we developed FH-graphene-MoS2 hybrid nanosheets which enabled efficient adsorption of radioactive ions through the photodegration of organics. In the hybrid material, graphene nanosheets coated FH nanoframes with considerable surface area serves as adsorption agent, together with the deposited MoS2 nanosheets as photodegradation material. Moreover, photoelectrons produced by MoS2 further promoted the adsorption ability by reducing the U(VI) to U(IV). In the treatment of wastewater which contains U(VI) and tannic acid (TA) under irradiation, the MoS2 in FH-graphene-MoS2 hybrid nanosheets decomposed TA and thus reduces the occupation of adsorption sites, which greatly promoted the adsorption capacity of FH-graphene hybrid nanosheets for U(VI).

Zircon ceramics (ZrSiO4) are promising candidates for actinide immobilization. Here, a series of Zr1-xNdxSiO4-x/2 (x = 0, 0.02, 0.20, and 1.0) ceramics are prepared to study the effects of phase evolution and acidity on the chemical durability of ZrSiO4-based nuclear waste forms. The results show that the chemical stability of the single-phase ZrSiO4 sample is better than that of the biphasic Zr0.8Nd0.2SiO3.9 sample due to the existence of a secondary highly soluble phase (Nd2Si2O7), which increases the contact area with leachate. The normalized release rates of both zirconium (Zr) and neodymium (Nd) in the Zr1-xNdxSiO4-x/2 ceramic waste forms increase with increasing Nd loading and acid concentration. LRZr in ZrSiO4 ceramics and LRNd in Zr0.98Nd0.02SiO3.99 ceramics are the lowest, while LRZr and LRNd reach the highest values in the Zr0.8Nd0.2SiO3.9 and Nd2Si2O7 ceramics, respectively. The normalized release rates of Zr are lower than those of Nd due to the difference in the energies of their bonds with oxygen atoms. Moreover, the changes in the surfaces of the leached ceramics are consistent with their leaching results.

Layered core-shell structured Fungus hyphae (FH)/Fe3O4/graphene oxide (GO) nanocomposite spheres (FFGS) were successfully prepared by successively culturing FH in Fe3O4 or GO containing mediums. This strategy was low-cost, eco-friendly and easy to scale up for the preparation of core-shell structured FH mediated materials. Batch adsorption results showed that the core-shell structured FFGS was much better in the adsorption of methyl violet (MV) and uranium (U (VI)) than FH, FH/GO, and FH/Fe3O4, which might be attributed to its lower zeta potential. Specifically, the maximum adsorption capacity of FFGS was calculated to be 117.35 and 219.71 mg/g for MV (pH 7.0) at 303 K, and U (VI) (pH 5.0) at 293 K, respectively. According to the adsorption kinetics and adsorption isotherms, the mechanism of U (VI) adsorption on FFGS was dependent on the chemical adsorption, while MV was mainly physical adsorption. Furthermore, attributed to its magnetic shell, the FFGS could easily realize controllable magnetic separation. Thus, core-shell structured FFGS would be a promising adsorbent for the removal and recovery of MV or U (VI) from waste water.

In this work, Bi

Amorphous calcium carbonate/chitosan (ACC/CS) nanocomposite films containing Mg-ACC (0–100 wt%) are prepared by simple natural evaporation-induced assembly. The influence of Mg-ACC content on the mechanical properties as well as cross-section of ACC-CS nanocomposite films were systematically investigated. The nanocomposite films exhibit an excellent mechanical property at Mg-ACC contents of 80 wt% compared to ordinary calcium carbonate/chitosan composites. With content of Mg-ACC increasing, the mechanical properties of ACC-CS nanocomposite films were further increased, reaching a maximum when the content of Mg-ACC to 80 wt%. Strength and Young's modulus of the 80 wt% ACC-CS nanocomposite film reach 121.67 MPa and 31.96 GPa, respectively, which is 2.3 and 5.1 times higher than that of the pure CS film. After undergoing Mg-ACC crystal transformation when the Mg-ACC content is greater than 80 wt%, the smooth structure was transformed into crystal-like agglomerates, which deteriorates mechanical properties. Furthermore, the as-prepared nanocomposite films show excellent hydrophobicity and high biocompatibilities for boosting the growth of Cell-293T. In addition, we also proposed a physical model for the dispersion of Mg-ACC in CS matrix, which could better explain the enhancement of the mechanical properties of nanocomposite films. The above results provide a comprehensive understanding of the development of high-performance bionic nanocomposites loaded with high nanofillers.

In this paper, fungus hyphae/graphene oxide (FH/GO) with interesting net structure was prepared through a simple biological culture method for U(VI) removal. SEM, Zeta potential, FT-IR and XPS were applied to characterize the physicochemical properties of the resulting FH/GO composites, and batch and column adsorption experiments were conducted to elucidate their U(VI) adsorption performances and mechanisms. Results showed that FH/GO composite was highly efficient in U(VI) adsorption with a high reusability and stability. Specifically, compared to biomass (FH), the U(VI) adsorption capacity was increased by 60% for FH/GO composite at initial pH 6.0 (±0.1) and 20 °C, and the maximum U(VI) adsorption capacity for the FH/GO was 199.37 mg/g. Furthermore, the adsorption kinetics, thermodynamics and isotherms analysis demonstrated that the U(VI) adsorption on FH/GO was depended on the chemical adsorption, and it was an endothermic and spontaneous process. Therefore, these results suggested that the as-prepared FH/GO composite was promising in nuclear waste water treatment.