Special topics

    TOPICAL REVIEW—Laser and plasma assisted synthesis of advanced nanomaterials in liquids

    Default Latest Most Read
    Please wait a minute...
    For selected: Toggle thumbnails
    Experimental study on gas production and solution composition during the interaction of femtosecond laser pulse and liquid
    Yichun Wang(王奕淳), Han Wu(吴寒), Wenkang Lu(陆文康), Meng Li(李萌), Ling Tao(陶凌), and Xiuquan Ma(马修泉)
    Chin. Phys. B, 2022, 31 (7): 070204.   DOI: 10.1088/1674-1056/ac7449
    Abstract94)   HTML1)    PDF (1098KB)(18)      
    The process of ionizing normal saline induced by femtosecond laser is studied from the perspective of gas production rate and composition. When the repetition rate is less than 1000 Hz, each laser pulse independently generates ionization gas. At the same time, we discovered the inhibitory effect of meglumini diatrizoici on the ionization process and explained the reasons for this inhibition. Finally, the gas composition proved that the primary gas production mechanism of the femtosecond laser is the decomposition of water molecular, and the composition of the solution after the reaction proved the decomposition effect of the laser on meglumine.
    Quantitative evaluation of LAL productivity of colloidal nanomaterials: Which laser pulse width is more productive, ergonomic, and economic?
    Alena Nastulyavichus, Nikita Smirnov, and Sergey Kudryashov
    Chin. Phys. B, 2022, 31 (7): 077803.   DOI: 10.1088/1674-1056/ac5602
    Abstract98)   HTML0)    PDF (10098KB)(22)      
    Near-IR (wavelength ≈ 1 μm) laser ablation of bulk, chemically-inert gold in water was compared for different laser pulse width in broad the range of 300 fs-100 ns, comparing a number of key ablation characteristics: mass loss, single-shot crater volume and extinction coefficient of the generated colloidal solutions taken in the spectral ranges of interband transitions and localized plasmon resonance. Comparing to related air-based ablation results, at the given fluences laser ablation in the liquid resulted in the maximum ablation yield per unit energy and maximum NP yield per pulse and per unit energy for the picosecond lasers, occurring at subcritical peak pulse powers for laser self-focusing. The self-focusing effect was demonstrated to yield in incomplete, effectively weaker focusing in the water filaments of ultrashort laser pulses with supercritical peak powers, comparing to linear (geometrical) focusing at sub-critical peak powers. At the other, nanosecond-pulse extreme the high ablation yield per pulse, but low ablation yield per unit energy and low NP yield per pulse and per unit energy were related to strong ablation plasma screening, providing mass removal according to the well-established scaling relationships for plasma. Illustrative comparison of the ablation and nanoparticle generation efficiency versus the broad fs-ns laser pulse width range was enabled in terms of productivity, economicity, and ergonomicity, using the proposed universal quantitative criteria.
    Laser fragmentation in liquid synthesis of novel palladium-sulfur compound nanoparticles as efficient electrocatalysts for hydrogen evolution reaction
    Guo-Shuai Fu(付国帅), Hong-Zhi Gao(高宏志), Guo-Wei Yang(杨国伟), Peng Yu(于鹏), and Pu Liu(刘璞)
    Chin. Phys. B, 2022, 31 (7): 077901.   DOI: 10.1088/1674-1056/ac4e0e
    Abstract124)   HTML2)    PDF (1279KB)(31)      
    One promising way to tune the physicochemical properties of materials and optimize their performance in various potential applications is to engineer material structures at the atomic level. As is well known, the performance of Pd-based catalysts has long been constrained by surface contamination and their single structure. Here, we employed an unadulterated top-down synthesis method, known as laser fragmentation in liquid (LFL), to modify pristine PdPS crystals and obtained a kind of metastable palladium-sulfur compound nanoparticles (LFL-PdS NPs) as a highly efficient electrocatalyst for hydrogen evolution reaction (HER). Laser fragmentation of the layered PdPS crystal led to a structural reorganization at the atomic level and resulted in the formation of uniform metastable LFL-PdS NPs. Noteworthy, the LFL-PdS NPs show excellent electrocatalytic HER performance and stability in acidic media, with an overpotential of -66 mV at 10 mA· cm-2, the Tafel slope of 42 mV· dec-1. The combined catalytic performances of our LFL-PdS NPs are comparable to the Pt/C catalyst for HER. This work provides a top-down synthesis strategy as a promising approach to design highly active metastable metal composite electrocatalysts for sustainable energy applications.
    Novel closed-cycle reaction mode for totally green production of Cu1.8Se nanoparticles based on laser-generated Se colloidal solution
    Zhangyu Gu(顾张彧), Yisong Fan(范一松), Yixing Ye(叶一星), Yunyu Cai(蔡云雨), Jun Liu(刘俊), Shouliang Wu(吴守良), Pengfei Li(李鹏飞), Junhua Hu(胡俊华), Changhao Liang(梁长浩), and Yao Ma(马垚)
    Chin. Phys. B, 2022, 31 (7): 078102.   DOI: 10.1088/1674-1056/ac6db2
    Abstract116)   HTML0)    PDF (5403KB)(22)      
    Non-stoichiometric copper selenide (Cu2-xSe, x=0.18~0.25) nanomaterials have attracted extensive attentions due to their excellent thermoelectric, optoelectronic and photocatalytic performances. However, efficient production of Cu2-xSe nanoparticles (NPs) through a green and convenient way is still hindered by the inevitable non-environmentally friendly operations in common chemical synthesis. Herein, we initially reveal the coexistence of seleninic acid content and elemental selenium (Se) NPs in pulsed laser-generated Se colloidal solution. Consequently, we put forward firstly a closed-cycle reaction mode for totally green production of Cu1.8Se NPs to exclude traditional requirements of high temperature and toxic precursors by using Se colloidal solution. In such closed-cycle reaction, seleninic acid works as the initiator to oxidize copper sheet to release cuprous ions which can catalyze the disproportion of Se NPs to form SeO32- and Se2- ions and further produce Cu2-xSe NPs, and the by-product SeO32- ions promote subsequent formation of cuprous from the excessive Cu sheet. In experiments, the adequate copper (Cu) sheet was simply dipped into such Se colloidal solution at 70 ℃, and then the stream of Cu1.8Se NPs could be produced until the exhaustion of selenium source. The conversion rate of Se element reaches to more than 75% when the size of Se NPs in weakly acidic colloidal solution is limited between 1 nm and 50 nm. The laser irradiation duration shows negative correlation with the size of Se NPs and unobvious impact to the pH of the solution which both are essential to the high yield of Cu1.8Se NPs. Before Cu sheet is exhausted, Se colloidal solution can be successively added without influences to the product quality and the Se conversion rate. Such green methodology positively showcases a brand-new and potential strategy for mass production of Cu2-xSe nanomaterials.
    Up/down-conversion luminescence of monoclinic Gd2O3:Er3+ nanoparticles prepared by laser ablation in liquid
    Hua-Wei Deng(邓华威) and Di-Hu Chen(陈弟虎)
    Chin. Phys. B, 2022, 31 (7): 078701.   DOI: 10.1088/1674-1056/ac5399
    Abstract108)   HTML0)    PDF (1580KB)(25)      
    Multifunctional luminescent materials are attracting attention nowadays. In this work, monoclinic Gd2O3:Er3+ nanoparticles, which possess up-conversion luminescence and down-conversion luminescence properties, were successfully synthesized by laser ablation in liquid (LAL) technique. Up-conversion luminescence and down-conversion luminescence of monoclinic Gd2O3:Er3+ nanoparticles were got under the excitation of 980 nm and 379 nm, respectively. In addition, tunable luminescence was got. Furthermore, the cytotoxicity of the nanoparticles is low and the fluorescence of the nanoparticles in cell is also strong enough. The results indicate that the Gd2O3:Er3+ nanoparticles synthesized by LAL technique are promising candidates for bio-imaging or other fields that require controllable fluorescence.
    Onion-structured transition metal dichalcogenide nanoparticles by laser fabrication in liquids and atmospheres
    Le Zhou(周乐), Hongwen Zhang(张洪文), Qian Zhao(赵倩), and Weiping Cai(蔡伟平)
    Chin. Phys. B, 2022, 31 (7): 076106.   DOI: 10.1088/1674-1056/ac539c
    Abstract134)   HTML1)    PDF (4620KB)(33)      
    Since the discovery of transition metal dichalcogenide (TMDC) nanoparticles (NPs) with the onion-like structure, many efforts have been made to develop their fabrication methods. Laser fabrication (LF) is one of the most promising methods to prepare onion-structured TMDC (or OS-TMDC) NPs due to its green, flexible, and scalable syntheses. In this mini-review article, we systematically introduce various laser-induced OS-TMDC (especially the OS-MoS2) NPs, their formation mechanism, properties, and applications. The preparation routes mainly include laser ablation in liquids and atmospheres, and laser irradiation in liquids. The various formation mechanisms are then introduced based on the different preparation routes, to describe the formations of the corresponding OS-NPs. Finally, some interesting properties and novel applications of these NPs are briefly demonstrated, and a short outlook is also given. This review could help to understand the progress of the laser-induced OS-TMDC NPs and their applications.