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PdCu alloy anchored defective titania for photocatalytic conversion of carbon dioxide into methane with 100% selectivity

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Journal of Energy Chemistry 2024年第4期91卷 254-265页

作者： Lina Zhang Sajjad Hussain Qiuye Li Jianjun Yang national&local joint engineering research center for Applied technology of Hybrid Nanomaterials Henan UniversityKaifeng 475004HenanChina

The photoreduction of CO_(2)into CH_(4)with simultaneous high activity and selectivity is a promising strategy to increase energy supply and alleviate global warming.However,the absence of the active sites that is responsible for the adsorption and activation of CO_(2)and the generation of CO and H2via side reactions often lead to poor efficiency and low selectivity of the catalyst.Herein,Cu,Pd,and PdCu metal clusters cocatalyst-anchored defective TiO_(2)nanotubes(Cu/TiO_(2)-SBO,Pd/TiO_(2)-SBO,and Pd1Cu1/TiO_(2)-SBO)were designed via a simple solution impregnation reduction and applied for photocatalytic conversion of CO_(2)to CH_(4).The Pd1Cu1/TiO_(2)-SBO photocatalyst exhibits excellent catalytic performance among the other catalysts for photoreduction of CO_(2)into CH_(4).More interestingly,the product selectivity of CH_(4)reaches up to 100%with a rate of 25μmol g^(-1)h^(-1).In-situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS)and density functional theory(DFT)simulations indicate that the main reasons for the high selectivity of CH_(4)are attributed to the PdCu alloy and oxygen vacancies,which jointly enhance the photoinduced carrier separation and lower energy barriers of key intermediates.Moreover,due to the tunable d-band center of the Cu site in the PdCu alloy,the generated intermediates can be well prevented from poisoning and promoted to participate in further reactions.Hopefully,the current study will provide insight into the development of new,highly selective photocatalysts for the visible light-catalytic reduction of CO_(2)into CH_(4).

关键词： PdCu alloy Defective TiO_(2) Photoreduction of CO_(2) Photocatalytic mechanism

Photocatalytic applications and modification methods of two-dimensional nanomaterials:a review

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Tungsten 2024年第1期6卷 77-113页

作者： Fan Yang Ping Hu Fan Yang Xing-Jiang Hua Bo Chen Lili Gao Kuai-She Wang School of Metallurgy engineering Xi’an University of Architecture and TechnologyXi’an 710055China national and local joint engineering research center for Functional Materials Processing Xi’an University of Architecture and TechnologyXi’an 710055China

Due to its unique electronic structure and special size effect,two-dimensional(2D)nanomaterials have shown great potential far beyond bulk materials in the field of photocatalysis.How to deeply explore the photocatalytic mechanism of 2D nanomaterials and design more efficient 2D semiconductor photocatalysts are research hotspots.This review provides a comprehensive introduction to typical 2D nanomaterials and discusses their current application status in the field of photocatalysis.The effects of material properties such as band structure,morphology,crystal face structure,crystal structure and surface defects on the photocatalytic process are discussed.The main modification methods are highlighted,including doping,noble metal deposition,heterojunction,thickness adjustment,defect engineering,and dye sensitization in 2D material systems.Finally,the future development of 2D nanomaterials is prospected.It is hoped that this paper can provide systematic and useful information for researchers engaged in the field of photocatalysis.

关键词： Photocatalysis Two-dimensional Nanomaterials Bandgap Modification strategy

Microstructural evolution and deformation behavior of friction stir welded twin-induced plasticity steel

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Journal of Materials Science & technology 2024年第2期169卷 68-81页

作者： Ke Qiao Kuaishe Wang Jia Wang Zhengyang Hao Yating Xiang Peng Han Jun Cai Qi Yang Wen Wang School of Metallurgical engineering National and Local Joint Engineering Research Center for Functional Materials ProcessingXi’an University of Architecture and TechnologyXi’an 710055China Shanghai research Institute of Materials Shanghai 200437China

The weldability of twin-induced plasticity(TWIP)steel with ultra-high strength via friction stir welding(FSW)technique was investigated,and microstructural evolution and deformation behavior of whole and micro-zones of FSW TWIP joint were studied for the first time.The results showed that the content of recrystallized grains in the stir zone(SZ)increased from 10.5%of basal material(BM)to 14.2%,and that of heat affected zone(HAZ)increased to 78.6%.The percentage of annealing twins decreased from 26.8%in BM to 11%in SZ,while increased to 35%in HAZ.Compared with the BM,the ultimate tensile strength and yield strength of the FSW joint increased to 1036 and 550 MPa,respectively,reaching 106.7%and 110.9%of BM,respectively.The elongation of the entire joint was 50.5%,which was lower than that of BM due to the nonuniform deformation during the tensile test.The engineering strain was mainly concentrated in BM and SZ and transferred to each other during the tensile test,while the engineering strain in HAZ was always the lowest.Finally,the tensile fracture occurred in the SZ.The order of ultimate tensile strength of micro-zones in the FSW joint was as follows:HAZ>BM≈SZ.The order of yield strength was as follows:HAZ>BM>SZ.

关键词： Twin-induced plasticity steel Friction stir welding Microstructure Mechanical property Deformation behavior

Precise regulation of the phase transformation for pyrolusite during the reduction roasting process

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International Journal of Minerals,Metallurgy and Materials 2024年第1期31卷 81-90页

作者： Ruofeng Wang Peng Gao Shuai Yuan Yanjun Li Yingzhi Liu Cheng Huang School of Resources and Civil engineering Northeastern UniversityShenyang 110819China national-local joint engineering research center of High-efficient Exploitation technology for Refractory Iron Ore Resources Shenyang 110819China

The mechanism involved in the phase transformation process of pyrolusite (MnO_(2)) during roasting in a reducing atmosphere was systematically elucidated in this study,with the aim of effectively using low-grade complex manganese ore resources.According to single-factor experiment results,the roasted product with a divalent manganese (Mn^(2+)) distribution rate of 95.30% was obtained at a roasting time of 25 min,a roasting temperature of 700℃,a CO concentration of 20at%,and a total gas volume of 500 mL·min^(-1),in which the manganese was mainly in the form of manganosite (MnO).Scanning electron microscopy and Brunauer–Emmett–Teller theory demonstrated the microstructural evolution of the roasted product and the gradual reduction in the pyrolusite ore from the surface to the core Thermodynamic calculations,X-ray photoelectron spectroscopy,and X-ray diffractometry analyses determined that the phase transformation of pyrolusite followed the order of MnO_(2)→Mn_(2)O_(3)→Mn_(3)O_(4)→MnO phase by phase,and the reduction of manganese oxides in each valence state proceeded simultaneously.

关键词： pyrolusite phase transformation reduction roasting microstructural evolution reaction mechanism

Recent process developments in beneficiation and metallurgy of rare earths:A review

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Journal of Rare Earths 2024年第4期42卷 629-642页

作者： Shaokai Cheng Wenbo Li Yuexin Han Yongsheng Sun Peng Gao Xiaolong Zhang School of Resources and Civil engineering Northeastern UniversityShenyang110819China national-local joint engineering research center of High-efficient Exploitation technology for Refractory Iron Ore Resources Shenyang110819China

Rare earth elements(REEs)are irreplaceable materials supporting low-carbon technology and equip-ment,and their commercial demand and strategic position are becoming increasingly prominent.With the continuous depletion of rare earth(RE)resources,developing high-efficiency beneficiation and eco-friendly metallurgical processes has attracted widespread attention.This paper reviews the major minerals exploited for RE production and their deposits,as well as the beneficiation and metallurgical processes of RE minerals.Bastnaesite,monazite,mixed RE ores,and ion-adsorption clays are the main raw materials in the world to date.RE-bearing ores(except ion-adsorption minerals)are generally beneficiated by flotation,gravity and magnetic separation techniques.The mainstream metallurgical processes for bastnaesite,monazite and mixed RE concentrates are oxidation roasting-HCl leaching,caustic soda decomposition and high-temperature concentrated sulfuric acid roasting,respectively.Ion-adsorption clays are directly processed by in situ leaching-precipitation/solvent extraction.To achieve the sustainable development of RE resources,it is essential to further explore innovative techniques to achievecomprehensive utilization and cleaner production.

关键词： Rare earths Beneficiation processes Metallurgical processes Cleaner production

Interface engineering of Titanium Nitride Nanotube Composites for Excellent Microwave Absorption at Elevated Temperature

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Nano-Micro Letters 2024年第9期16卷 147-160页

作者： Cuiping Li Dan Li Shuai Zhang Long Ma Lei Zhang* Jingwei Zhang Chunhong Gong College of Chemistry and Molecular Sciences Henan UniversityKaifeng 475004People’s Republic of China national and local joint engineering research center for Applied technology of Hybrid Nanomaterials Henan UniversityKaifeng 475004People’s Republic of China

Currently,the microwave absorbers usually suffer dreadful electromagnetic wave absorption(EMWA)performance damping at elevated temperature due to impedance mismatching induced by increased conduction loss.Consequently,the development of high-performance EMWA materials with good impedance matching and strong loss ability in wide temperature spectrum has emerged as a top priority.Herein,due to the high melting point,good electrical conductivity,excellent environmental stability,EM coupling effect,and abundant interfaces of titanium nitride(TiN)nanotubes,they were designed based on the controlling kinetic diffusion procedure and Ostwald ripening process.Benefiting from boosted heterogeneous interfaces between TiN nanotubes and polydimethylsiloxane(PDMS),enhanced polarization loss relaxations were created,which could not only improve the depletion efficiency of EMWA,but also contribute to the optimized impedance matching at elevated temperature.Therefore,the TiN nanotubes/PDMS composite showed excellent EMWA performances at varied temperature(298-573 K),while achieved an effective absorption bandwidth(EAB)value of 3.23 GHz and a minimum reflection loss(RLmin)value of−44.15 dB at 423 K.This study not only clarifies the relationship between dielectric loss capacity(conduction loss and polarization loss)and temperature,but also breaks new ground for EM absorbers in wide temperature spectrum based on interface engineering.

关键词： TiN nanotubes Interface engineering Polarization loss Impedance matching Electromagnetic wave absorption performance

EBSD analysis of grain boundary evolution and dynamic recrystallization of Inconel 625 superalloy at various hot spinning feed rates

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Progress in Natural Science:Materials International 2024年第1期34卷 56-65页

作者： Zhanjie Jing Jiangkun Fan Xudong Liu Yuelin Song Zixiao Wang Kai Cao Yuetan Chen Heng Fu Jianing Zhang Jinshan Li State Key Laboratory of Solidification Processing Northwestern Polytechnical University Chongqing Innovation center Northwestern Polytechnical University national&local joint engineering research center for Precision Thermoforming technology of Advanced Metal Materials

Hot spinning can make the material withstand shear stress, so that the shape of the material has a great change,which is one of the main processing methods of nickel-based alloy plate members. Inconel 625 alloy, which has excellent high temperature mechanical properties and can be used as the main candidate material for aerospace applications, needs further study on its hot spinning deformation behavior and deformation mechanism. In this paper, the effect of feed rate on the microstructure evolution of Inconel 625 superalloy was studied by the electron backscattered diffraction technology. The microstructure with necklace-like structures composed of dynamic recrystallization(DRX) grains was observed after hot spinning. It was found that at the low feed rate, the promotion of DRX degree and grain refinement happened, where the grain size reached the trough of 10.99 μm under a feed rate of 300 mm/min. However, with the further feed rate rising, the degree of DRX was suppressed to a certain extent and grain size increased to 14.26 μm. On balance, the feed rate of 300 mm/min was the most efficient condition for grain refinement. Besides, it was revealed that both discontinuous dynamic recrystallization(DDRX) and continuous dynamic recrystallization(CDRX) occurred during hot spinning. DDRX includes the initial grain boundary nucleation by bulging and the annealing twin boundary assisted nucleation, while the CDRX mechanism is related to the continuous subgrain rotation within the deformed grain. DDRX is the main DRX mechanism.

关键词： Inconel 625 superalloy Hot spinning Grain boundary evolution DRX mechanism

Chemotactic nanomotor for multimodal combined therapy of glioblastoma

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Science China Chemistry 2024年第4期67卷 1277-1288页

作者： Ting Li Lin Chen Yunxin Xue Xiangyu Xiao Wenjun Dai Kaiyuan Tan Tiantian Chen Yingfang Tao Chun Mao Jian Shen Mimi Wan national and local joint engineering research center of Biomedical Functional Materials School of Chemistry and Materials ScienceNanjing Normal UniversityNanjing 210023China

Glioblastoma(GBM) is the most aggressive malignant brain tumor. Due to the infiltration and heterogeneity of GBM, the obstruction of the blood-brain barrier(BBB) and the unique immunosuppressive mechanism, it is hard to achieve significant effects of GBM treatment. Here, a kind of chemotactic nanomotor that loaded with glucose oxidase(GOx) and carboxylated cisplatin(Pt(IV)) prodrug on the L-arginine-derived polymer is proposed. The nanomotors are driven by catalysis of glucose decomposition and the positive chemotaxis towards the GBM microenvironment where inducible nitric oxide synthase and reactive oxygen species are highly expressed. This facilitates the BBB crossing and GBM targeting of the nanomotors. In addition, the released nitric oxide(NO) during propulsion as well as the loaded GOx and Pt(IV) can exert combined NO/starvation/chemotherapy. Meanwhile, it is able to induce and enhance the immune response through multiple pathways, thus better coping with the complexities of GBM treatment.

关键词： chemotaxis combined therapy glioblastoma nanomotors

Complementary multicolor electrochromic devices with excellent stability based on porous tin oxide nanosheet scaffold

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Nano research 2024年第4期17卷 3035-3042页

作者： Chenchen Bian Jinhui Wang Huanhuan Liu Yin Yan Ping Zhang Weilong Yang Sensen Jia Xiaodan Guo Guofa Cai Key Laboratory for Special Functional Materials of Ministry of Education National&Local Joint Engineering Research Center for High-Efficiency Display and Lighting TechnologySchool of Materials and Engineeringand Collaborative Innovation Center of Nano Functional Materials and ApplicationsHenan UniversityKaifeng 475004China

Electrochromic devices(ECDs)have been extensively investigated as promising candidates in broad cutting-edge applications,such as smart windows,electronic labels,adaptive camouflage,etc.However,they have suffered from either inadequate color variations or poor cycling stability for a long time.Herein,we developed a general strategy to boost the cyclic stability and enrich the color variations of ECDs by scrupulous design of the composition and nanostructure of electrodes,in which porous tin oxide(SnO_(2))nanosheets serve as the scaffold and typical metal oxides or conducting polymers as the active electrochromic materials.Various electrochromic composite materials,including polyaniline(PANI)@SnO_(2),V2O5@SnO_(2),and WO_(3)@SnO_(2) heterostructured nanoarrays were prepared by the facile wet-chemical method.These composite electrodes exhibit remarkable electrochromic performances,e.g.,superior cycling stability(more than 2000 cycles),rich color variations(more than 5 colors for PANI@SnO_(2)),and enlarged optical modulation.These excellent performances account for the heterogenous porous nanoarrays,which not only facilitate the intercalation/extraction of ions but also relieve the stress generated during the electrochemical process.In addition,diverse prototypes of complementary multicolor ECD with excellent cycling stability(over thousands of cycles)and rich color variations(8 colors)were realized for the first time.We believe that our work put forward a general strategy for developing high-quality multicolor complementary electrochromic devices.

关键词： electrochromism tin oxide metal oxide cycling stability multicolor complementary device