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The high dielectric loss tangent value of black phosphorus nanosheets enables them to be selectively heated under microwave radiation to realize the in situ surface reaction of BP with Ni2+ to prepare thermodynamically unstable two-dimensional Ni2P. [ABSTRACT FROM AUTHOR]

Developing advanced noble-metal-free electrocatalysts for the hydrogen evolution reaction (HER) is still a great challenge. Herein, a novel HER catalyst with quasi zero-dimensional (0D) MoS 2 quantum dots (QDs) supported on two-dimensional (2D) Ti 3 C 2 T x MXene nanosheets is facilely synthesized. The MoS 2 QDs/Ti 3 C 2 T x nanohybrid retains the unique layer structure, and the MoS 2 QDs are in situ formed and distributed uniformly. The obtained MoS 2 QDs/Ti 3 C 2 T x catalyst exhibits superior electrocatalytic activity due to its excellent conductivity, abundant of active sites exposed and a high percentage of 1T metallic phase (∼76%) of MoS 2 QDs. Remarkably, an early HER overpotential of 220 mV at 10 mA cm−2 and a small Tafel slope of 72 mV dec−1 of MoS 2 QDs/Ti 3 C 2 T x are achieved in 0.5 M H 2 SO 4 solution. In addition, the exchange current density of MoS 2 QDs/Ti 3 C 2 T x is ∼5 times larger compared with pure MoS 2 , thus demonstrating an accelerated charge transfer during the electrocatalytic process. [Display omitted] • A facile strategywas developed to synthesize MoS 2 QDs on Ti 3 C 2 T x MXene. • The catalyst contains highly conductive 1T phase MoS 2 and rich accessibleactive sites. • MoS 2 QDs/Ti 3 C 2 T x shows outstanding electrocatalytic performance towards HER. [ABSTRACT FROM AUTHOR]

Abstract In this study, a novel carbon nanotube (CNT)-supported CuCo catalyst was successfully synthesized by wet impregnation. Experimental and theoretical results on catalytic deoxygenation of stearic acid, a model compound of microalgal bio-oil, revealed that the CuCo catalyst can effectively inhibit cracking reactions and promote production of diesel-like hydrocarbons. CuCo particles in the pores of CNTs were conducive to conversion of stearic acid to long-chain alkanes, featuring a high selectivity of 94.82% at 100% conversion. CuCo catalyst in oxidation state underwent fast in-situ reduction at the beginning of deoxygenation reaction, and its catalytic performance was comparable to that of reduced CuCo catalyst. The improved catalytic conversion of stearic acid to diesel-like hydrocarbons can be achieved at a high ratio of Cu0/(Cu++Cu0) and lattice Co atoms. In addition, the reduced H 2 pressure and amounts of catalysts show potential for large-scale industrial applications. Highlights • The CuCo catalyst can inhibit cracking and promote production of alkanes. • The CuCo catalyst can undergo fast in-situ reduction under reaction system. • Synergistic effect of Cu and Co mainly focuses on promoting reduction progress. • High ratio of Cu0/(Cu++Cu0) and lattice Co atoms are vital for catalytic activity. [ABSTRACT FROM AUTHOR]

Hydrotreatment of heteroatomic model compounds in microalgae-based bio-oils into diesel-like hydrocarbons was carried out over carbon nanotubes (CNTs)-supported β-Mo 2 C catalyst with superior activity and selectivity under a mild condition (≤200 °C). The results show that stearic acid and hexadecanamide can be completely converted into n -C 15 –C 18 alkanes over β-Mo 2 C/CNTs catalyst. The β-Mo 2 C/CNTs favors the pathway of hydrogenation–dehydration–hydrogenation to produce n -octadecane with an optimal yield of 91.24% at a lower temperature of 180 °C during hydrotreating process of stearic acid. The recycle tests demonstrate that the β-Mo 2 C/CNTs exhibits excellent stability, and can be reused for seven times consecutively without reduction of catalytic stability. Based on the determined products, a brief reaction pathway is proposed. Therefore, a novel approach to produce diesel-like hydrocarbons via catalytic hydrotreatment of microalgae-based bio-oils over β-Mo 2 C/CNTs is introduced, which provides a basic research as well as technical parameters for its further industrialization. [ABSTRACT FROM AUTHOR]

The ability to control size, shape and functionality of pores in materials is of fundamental importance to understanding sorption (host-guest) phenomena. We present a coordination polymer compound with narrow pores lined by free amine functionalities. Cu(aminotriazole)(1,4-dihydrogenphosphonate)hydrate, 1, forms a pillared layered structure where alternating pillaring units are replaced by the N-heterocycle to generate the pores. Single-crystal and powder X-ray diffraction data are presented as well as the thermogravimetric analysis and CO2, N2 and H2 gas sorption analyses. [ABSTRACT FROM AUTHOR]

Developing Fe 2 O 3 -based anode materials with high electrical conductivity and structure stability is crucial for high-performance lithium-ion batteries (LIBs). Herein, we design a MXene-confined mesoporous γ-Fe 2 O 3 nanosphere architecture via the in-situ formation of hydrogen bonds under alkali treatment. The mesoporous γ-Fe 2 O 3 nanosphere consisting of nanocrystalline subunits is wrapped by Ti 3 C 2 T x MXene, which acting as the shield can effectively mitigate the volume change of γ-Fe 2 O 3 nanosphere and guarantee a fast electron flow. The distinctive porous structure of as-prepared γ-Fe 2 O 3 @Ti 3 C 2 T x electrode can provide a large electrode-electrolyte interface and accessibility of active sites to accelerate the electrochemical activity. With the assistance of hydrogen bonds, the structural and interfacial stabilities of γ-Fe 2 O 3 @Ti 3 C 2 T x can be obviously enhanced, leading to a connected conductive-network to facilitate the diffusion kinetics and cycle stability. The galvanostatic intermittent titration technique (GITT) analysis further confirms the Li+ diffusion coefficient (D GITT ) of γ-Fe 2 O 3 @Ti 3 C 2 T x composite by alkali treatment are improved. As a consequence, the obtained γ-Fe 2 O 3 @Ti 3 C 2 T x anode for LIBs delivers an ultrahigh reversible capacity of 1060 mA h g−1 at 0.5 A g−1 after 400 cycles and an excellent long-term stability without obvious capacity loss (466 mA h g−1 after 800 cycles at 2 A g−1). [Display omitted] • The MXene-confined mesoporous γ-Fe 2 O 3 nanosphere architecture was synthesized. • Structural stability of γ-Fe 2 O 3 @Ti 3 C 2 T x was enhanced by formation of hydrogen bonds. • The Li+ diffusion of γ-Fe 2 O 3 @Ti 3 C 2 T x after alkali treatment can be accelerated. • The γ-Fe 2 O 3 @Ti 3 C 2 T x electrode delivers an outstanding lithium storage performance. [ABSTRACT FROM AUTHOR]

A bis(phosphonatemonoester) is employed as a linker in a Zn(ii) metal organic framework. The complex is a layered structure pillared only by vdW interactions between alkyl groups. Nonetheless, permanent pores are formed as confirmed by PXRD and gas sorption analysis. [ABSTRACT FROM AUTHOR]

Degradation activities of catalysts can be enhanced by building a hexagonal/monoclinic tungsten oxide (WO 3) phase junction (h/m-WO 3) on their surfaces. Through proper composition regulation, a well matched energy structure formed, which proved to be beneficial for separation and transfer efficiency of electron-hole pairs in WO 3. Besides of that, in this h/m-WO 3 junction system, main active species were O 2 − and h+. Electron and hole in valence band can be consumed simultaneously. In this condition, separation rate of electron-hole pairs would be further promoted, and finally induce an enhanced photocatalysis property. • An controllable h/m-WO 3 phase junction preparation method was proposed. • The compositions of h-WO 3 in h/m-WO 3 have a great impact on their photocatalytic activities. • Charge separation and migration properties of WO 3 can be improved by proper junction regulations. Photogenerated carriers separation is the bottleneck step to determine the photocatalytic efficiency in photocatalysis. Fabrication of the phase junction has been demonstrated to be efficient in the photogenerated carriers separation. It is important to control the phase composition in phase junction. In this work, photoatalysts with tunable hexagonal/monoclinic WO 3 phase junction (h/m-WO 3) were prepared by presice controlling the h-WO 3 → m-WO 3 phase transformation. Based on in-situ XRD results, a suitable calcination temperature (400 °C) was selected to realize the phase transition from h-WO 3 to m-WO 3. It is found that the junction structures can be easily regulated with increasing calcination time at 400 °C. The photocatalytic degradation of RhB results indicate that h/m-WO 3 sample with 88.1 wt% h-WO 3 exhibits the maximum value. The results from electrochemical impedance spectroscopy (EIS) and surface photovoltage (SPV) indicate that the separation of photogenerated carriers can be greatly improved by the phase regulation in WO 3 with phase junction. [ABSTRACT FROM AUTHOR]

• Lipase is covalently bonded onto the surface of Ti 3 C 2 T X nanosheets. • The immobilized lipase shows an enhanced activity after NIR light irradiation. • The improved activity may be due to the excellent photothermal effect of Ti 3 C 2 T X. • The immobilized lipase exhibits good pH, thermal stability and reusability. The rational design of new supports is critical for modern enzyme immobilization for advanced biocatalysis. Meanwhile, utilizing the photothermal effect of the support to achieve optical remote control of enzymatic activity remains a huge challenge. MXene, owing to its rich surface functional groups, biological compatibility and excellent photothermal effect, is a promising support material to satisfy the above requirements. Herein, a facile method to covalently bond lipase onto the surface of Ti 3 C 2 T X nanosheets through the coordination interaction with aminosilane ligand spacers is reported. The enzymatic activities of immobilized lipase are tuned based on the photothermal properties of Ti 3 C 2 T X nanosheets by exposure to near-infrared (NIR) light. The immobilized lipase shows an enhanced catalytic activity for the hydrolysis of p-nitrophenylpalmitate (pNPP) after NIR irradiation. In addition, immobilized lipase exhibits good pH, thermal stability and reusability, which are important in practical uses of enzymes. [ABSTRACT FROM AUTHOR]

The nutrient availability of carbon (C), nitrogen (N), and phosphorus (P) has been decreasing due to a decline in the biological function of yellow soil, limiting potato yield (PY). Increasing biochar or organic fertilizer input is an effective way to improve soil microbiological fertility. However, indexes to regulate soil microbiological fertility using biochar and organic fertilizer individually or in combination and these indexes' associations with PY remain unclear. In this study, four fertilization strategies were developed using the nutrient balance method: CK (recommended NPK fertilization), BC (NPK + biochar), OF (NPK + organic fertilizer), and BF (NPK + 1/2 biochar + 1/2 organic fertilizer). Using different fertilization strategies, the eco-stoichiometry characteristics of the soil microbial biomass and enzyme activity; the bioavailability of C, N, and P; and the differences in PY were investigated, and the direct and indirect effects of these factors on PY were determined over a two-year period. The results showed that exogenous organic matter input could considerably affect the stoichiometric ratios of soil microbial biomass; C; N; P; the stoichiometric ratios of C-converting, N-converting, and P-converting enzyme activities (expressed as BG+CBH, NAG+LAP, and AP, respectively); and the integrated enzyme index (IEI). The IEI was the highest in BF, followed by OF, BC, and CK. A significant positive correlation was found between the microbial biomass C, N, and P and their corresponding converting enzyme activities (p < 0.05). The ln(BG+CBH):ln(NAG+LAP), ln(BG+CBH):lnAP, and ln(NAG+LAP):lnAP ratios were all higher than 1:1, but they approached 1:1 in the order of CK-BC-OF-BF. Compared to soil C and N, P-converting enzyme activity was the primary limiting factor for soil nutrient conversion in the study area. BF was less restricted by P and more balanced in its nutrient ratio. The microbial biomass C:N:P could affect PY in eight ways. (1) Microbial biomass C:N directly decreased PY, and microbial biomass C:P indirectly increased PY. (2) It could decrease C-converting enzyme activity, (3) decrease N availability to increase C-converting enzyme activity, (4) decrease P availability, or (5) decrease P availability to decrease the soil C:P-converting enzyme activity ratio. Microbial biomass N:P indirectly increased PY (6) by increasing the soil C:P-converting enzyme activity ratio, (7) by increasing C-converting enzyme activity, or (8) by increasing N availability to increase C-converting enzyme activity. Thus, BF is an effective strategy for regulating the soil microbiological fertility index; enhancing C, N, and P nutrient conversion; and increasing PY. The input of exogenous organic matter can alter the stoichiometric ratios of soil microbial biomass C, N, and P; the stoichiometric ratios of C-converting, N-converting, and P-converting enzyme activities; and nutrient availability, thus regulating PY. Microbial biomass N:P and soil C:P-converting enzyme activity ratios influence PY the most. [ABSTRACT FROM AUTHOR]

It is well‐known that photogenerated charge separation is the key and bottleneck step to determine the solar energy efficiency in photocatalysis. Although strategies for facilitating spatial charge separation of semiconductor‐based photocatalysts like heterojunctions, especially for heterophase junctions have been recognized as useful and adequate approaches, the original morphology‐tailored structures are always challenging to be maintained during the thermal‐induced phase transformation process. Herein, using a facile self‐templated method, we successfully fabricate heterophase junction into the well‐defined hierarchical porous structure of visible‐light‐responsive semiconductor, bismuth oxide (Bi2O3), without destroying the its unique hierarchical porous morphology. Such organic integration of heterophase junction and hierarchical porous structure are demonstrated to enable highly efficient separation of photogenerated electrons and holes, resulting in a remarkable enhancement in photocatalytic activities. Our work showcases a general concept for developing artificial photocatalyst systems via integrating efficient charge separation path into the unique morphology‐tailoring of semiconductors for highly efficient solar energy conversion. [ABSTRACT FROM AUTHOR]

[Display omitted] • Electrochemical investigation of frying oils is presented. • Impedance spectroscopy captures the electrical polarization state of the frying oils. • 6 types of frying oil, inclusive of 52 frying time points are analyzed. • The ML-based model predicts TPC content in frying oil test samples. • This work has potential for POC tool for in situ TPC prediction of frying oils. Standard approaches to determining the total polar compounds (TPC) content in frying oils such as the chromatographic techniques are slow, bulky, and expensive. This paper presents the electrochemical analysis of 6 types of frying oils inclusive of 52 frying timepoints, without sample preparation. This is achieved via impedance spectroscopy to capture sample-specific electrical polarization states. To the best of our knowledge, this is a first-of-its-kind comprehensive study of various types of frying oils, with progressively increasing frying timepoints for each type. The principal component analysis distinguishes the frying timepoints well for all oil types. TPC prediction follows, involving supervised machine learning with sample-wise leave-one-out implementation. The R2 values and mean absolute errors across the test samples measure 0.93–0.97 and 0.43–1.19 respectively. This work serves as a reference for electrochemical analysis of frying oils, with the potential for portable TPC predictors for rapid accurate screening of frying oils. [ABSTRACT FROM AUTHOR]

Bi-functional Ni/H-ZSM-22 catalysts with melt infiltration, incipient wetness impregnation and wet impregnation methods, were used to catalyze palmitic acid. Compared to parent zeolite, there were decrease of relative crystallinity, some blockage effects of micro pores and less strong acid sites after Ni loading. The complete conversion of palmitic acid and 100% alkanes selectivity were achieved at lower temperature (200 °C). No deactivation was observed in five recycle reaction, indicating the excellent catalytic performance and stability of Ni/H-ZSM-22 catalysts. Higher reaction temperature (240–260 °C), more iso -alkanes/ n -alkanes formed, while less C 16 /C 15 produced. Additionally, the catalysts prepared by melt infiltration were more inclined to HDO routes and produced more iso -alkanes (0.8 mol ratio of iso -alkanes/ n -alkanes) than their counterparts prepared by conventional impregnation methods. [ABSTRACT FROM AUTHOR]

• The few-layered MoS 2 nanosheets with different phase contents were prepared by an efficient controllable phase engineering. • The optimized material shows outstanding specific capacity and excellent long cycling performances. • The mechanisms involved were elucidated by systematical characterizations. • The DFT simulations reveal that the 1T phase MoS 2 has much lower Zn diffusion energy barriers. Recently, aqueous rechargeable Zn-ion batteries have attracted extensive attention, owing to their low-cost, high operational safety and environmental friendliness. However, the aqueous zinc-ion battery is still in a very infant stage, and the main challenge is to develop the ideal cathode due to the sluggish kinetics and low reversibility of divalent zinc ions. Herein, for the first time, we report controllable phase engineered few-layered MoS 2 nanosheet as cathode materials for rechargeable aqueous Zn-ion batteries and systematically study their performance. We found that the obtained MoS 2 with different phase contents showed distinct performance in the rechargeable aqueous zinc-ion battery. In particular, the MoS 2 nanosheets with ~70% 1T phase content displays excellent specific capacity and shows outstanding long-term cyclic stability. The mechanisms involved were clarified by not only comprehensive characterizations, but also the density functional theory (DFT) simulations that reveal the 1T phase MoS 2 has much lower Zn diffusion energy barriers. This study provides new insight into the effect of different phases on the performance of MoS 2 -based electrodes and will improve our understanding of developing better cathodes for the aqueous rechargeable Zn-ion batteries. [ABSTRACT FROM AUTHOR]

Electrochemical water splitting plays an important role in alternative energy studies, since it is highly efficient and environment-friendly. Accordingly, it is an ideal way of providing alternative to meet the urgent need of finding sustainable and clean energy. This study presents the fabrication of CoP attached on multilevel N-doped CNT/graphene (CoP–CNT/NG) hybrids. The multilevel carbon structure can enhance electrical conductivity efficiently and increase the reaction active area immensely. The obtained electrocatalyst exhibits great electronic conductivity (17.8 s cm−1) and HER activity with low overpotential (155 mV at 10 mA cm−2), low Tafel slope (69.1 mV dec−1) in 0.5 M H 2 SO 4. In addition, the CoP–CNT/NG displays prominent electrochemical durability after 18 h. • A two-step strategy is used to synthesize composites. • The multilevel structure improve the electrical conductivity and reaction active area. • The hybrid exhibits high HER activities. • Interaction between CoP and carbon structure enhances the activity and stability. [ABSTRACT FROM AUTHOR]

Abstract: Aqueous‐phase ketonization of bio‐based acetic acid is important to improve the conversion efficiency of biomass resources. In this study, ZrMn mixed oxides (ZrMnOx) with high aqueous‐phase ketonization activity are synthetized through a carbonization/oxidation method (COM) and solvothermal method (STM). The results show that ZrMnOx prepared by COM possesses tetragonal ZrO2, and hausmannite Mn3O4 is observed only at a high oxidation temperature of 750 °C. Low‐temperature and long oxidation results in decreased crystallinity and crystallite size, which is related to highly dispersed Mnn+ species. The catalysts with improved acid sites possess high ketonization activity. Surface areas and pore size of ZrMnOx synthetized by STM are controlled by the solvents for thermal treatment. Compared with water as solvent, ethanol increases the surface area and pore size, resulting in high ketonization activity. [ABSTRACT FROM AUTHOR]

The low photocatalytic performance of a single photocatalyst mainly originates from a fast recombination of photogenerated charge carriers. Rational design and construction of direct solid-state Z-scheme photocatalysts is an effective approach to improve the charge separation efficiency of photogenerated electron–hole pairs. In this study, a series of Z-scheme In2S3/Ag2CrO4 composite photocatalysts with a different content of In2S3 were synthesized using a facile chemical precipitation method and characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy (UV-vis DRS), photoluminescence (PL) spectroscopy and photoelectrochemical measurements. The photocatalytic activity of the In2S3/Ag2CrO4 composites was evaluated through photodegradation of methyl orange (MO) under visible light irradiation (λ ＞ 420 nm). The results demonstrate that the optimal Z-scheme In2S3/Ag2CrO4 composite with a theoretical weight content of 4.0% In2S3 provided a photodegradation rate constant for MO of 0.0087 min−1, which is approximately 2.8 and 5.4 times higher than those of pure In2S3 and Ag2CrO4, respectively. The enhanced photocatalytic activity may be attributed to the formation of a Z-scheme system between In2S3 and Ag2CrO4, effectively prolonging the lifetime of the photoinduced electrons generated by In2S3 and the photoinduced holes generated by Ag2CrO4, which was subsequently confirmed using active species trapping experiments, photoluminescence techniques and photoelectrochemical assays. This work may be useful for rationally designing new types of Z-scheme photocatalysts and provides some illuminating insights into the Z-scheme charge transfer mechanism for application in the solar energy conversion and environmental remediation fields. [ABSTRACT FROM AUTHOR]

The liquid-phase deoxygenation reaction of palmitic acid has been investigated in a batch reactor over carbon nanotubes (CNTs)-supported MoO 2 and Pd catalysts under hydrogen atmosphere. The results showed that palmitic acid can be converted completely at 220 °C on MoO 2 /CNTs catalyst with high hexadecane selectivity (92.2%). The H 2 pressure of the reaction can control the product׳s selectivity. Compared with noble metal Pd-based catalyst, MoO 2 -based catalyst is a much better catalyst because of its high activity, selectivity, stability and low cost. Product distribution revealed that Pd offered high selectivity for pentadecane, whereas MoO 2 showed excellent selectivity for hexadecane, which showed more favorable atom efficiency. Therefore, the MoO 2 /CNTs catalyst can be regarded as an attractive candidate for catalytic hydrodeoxygenation of long-chain fatty acids to produce high-grade transportation biofuels. [ABSTRACT FROM AUTHOR]

This work has investigated the catalytic deoxygenation and denitrogenation of palmitic acid and hexadecanamide over supported Co catalysts to produce high yields of hydrocarbons. Palmitic acid and hexadecanamide were completely converted over Co/H-ZSM-22 catalyst with higher initial conversion rate within 10 min (0.151 and 0.036 mol L−1 h−1, respectively, for palmitic acid and hexadecanamide), compared to 0.045 and 0.027 molL−1 h−1 obtained over Co/SiO 2 catalyst. Characterization results revealed that neutral SiO 2 support was selective towards the hydrodecarbonylation (HDC) reaction, whereas H-ZSM-22 zeolite support with strong acid sites significantly improved the hydrodeoxygenation (HDO) and hydrodenitrogenation (HDN) reactions without carbon atom loss. Unlabelled Image • Co/H-ZSM-22 exhibited high activity of palmitic acid and hexadecanamide conversion. • Large pores and strong acid sites significantly increased catalytic performance. • Hexadecanamide restrained conversion of palmitic acid and isomerization. [ABSTRACT FROM AUTHOR]