The phase transformation process of nanoparticles prepared by pulsed laser irradiation was studied using photoacoustic signal.

Grain boundaries (GBs) engineering of hybrid perovskite films is of significance for accessing high performance perovskite solar cells (PSCs), owing to the abundant defect states existed therein originating from the low temperature film processing. Nanocrystals embedding at GBs has shown profound advantages in carrier dynamics modulation, while the surface defects on nanocrystals in turn lead usually to the trapping of carriers at GBs. The authors herein demonstrate the efficient GBs engineering via laser generated nanocrystals with tailored surface states for improved carriers dynamics and environmental stability of PSCs. The embedding of La doped BaSnO 3 (LBSO) nanocrystals with bare surfaces in perovskite provides an additional channel to facilitate the effective carrier extraction and reduce the carrier recombination, leading to a maximum power conversion efficiency (PCE) of 21.11% with negligible hysteresis for the mixed‐cation PSCs. To clarify the influence of surface defect states of the laser generated nanocrystals on the performance of PSCs, 1H,1H‐perfluorooctylamine is grafted on LBSO nanocrystals during the laser irradiation, resulting in improved champion PCE up to 21.65% and pronounced environmental stability. The universal embedding of the LBSO nanocrystals with tailored surface states in different perovskite by fabricating FAPbI 3 PSCs with a champion PCE of 23.74% is further demonstrated.

Compared with traditional solder joint bonding, an anisotropic conductive adhesive (ACA) provides an efficient and simple method for the interconnection of small-scale electronics. The wider applic...

Seeking strategies of promoting the charge separation and transport of the photo-active layer has been always of significance for the development of high-performance optoelectronic devices. We herein demonstrate an effective way of decorating WO3 nanocrystals in perovskite films for boosted photogenerated carriers transport. The WO3 nanocrystals are generated by a simple technique of pulsed laser irradiation in liquid, then introduced into the perovskite film based on the anti-solvent approach. Such decoration is found helpful for the increase of the short-circuit current density (Jsc) of the device, which leads to the increase of the photoconversion efficiency (PCE) from 17.72% to 19.29%. The improved PCE is mainly due to the decoration of the WO3 at the grain boundaries of perovskite films that facilitates the charge transport between the adjacent grains, which is evidenced by the quenching of the film photoluminescence, shortened carrier lifetime, and increased carrier mobility. We thus believe our study provides an effective way of embedding ordinary metal oxides in perovskite films for enhanced optoelectronic performance.

Creating colloids of liquid metal with tailored dimensions has been of technical significance in nano-electronics while a challenge remains for generating supranano (<10 nm) liquid metal to unravel the mystery of their unconventional functionalities. Present study pioneers the technology of pulsed laser irradiation in liquid from a solid target to liquid, and yields liquid ternary nano-alloys that are laborious to obtain via wet-chemistry synthesis. Herein, the significant role of the supranano liquid metal on mediating the electrons at the grain boundaries of perovskite films, which are of significance to influence the carriers recombination and hysteresis in perovskite solar cells, is revealed. Such embedding of supranano liquid metal in perovskite films leads to a cesium-based ternary perovskite solar cell with stabilized power output of 21.32% at maximum power point tracing. This study can pave a new way of synthesizing multinary supranano alloys for advanced optoelectronic applications.

Size tailored black BiVO4 colloids with rich oxygen vacancies were generated via facile laser processing for high performance sodium storage.

Correction for 'Preparation of carbon dots by non-focusing pulsed laser irradiation in toluene' by Huiwu Yu et al., Chem. Commun., 2016, 52, 819-822, DOI: ; 10.1039/C5CC08384B.

Rational manipulation of the carbon framework from the microporous to nonporous via a molecular design approach is interesting but challenging. Herein, we report a versatile strategy for transforming the microporous carbon framework to the low porous one by an elaborate molecular crosslinker design in the polystyrene (PS) precursor. Direct coupling of benzene rings in PS via Scholl reaction yields hypercrosslinked PS-derived carbon with low porous framework, while insertion of methylene crosslinker into PS via a solvent knitting strategy leads to microporous carbon framework. The results show that methylene crosslinker functions as molecular-scale soft templates for facilitating micropores, whereas direct linking PS chains promotes aromatization and mitigates micropore formation during the pyrolysis. The distinct carbon frameworks derived from similar precursor and pyrolysis condition provide an intriguing platform for structure-property relationship study, as preliminarily exemplified by the application in Na ion storage. The low-porosity carbon shows higher initial Coulombic efficiency and superior capacity thanks to its low surface area and enhanced Na insertion into pseudo-graphitic microcrystal structure. The present protocol opens up new avenues towards flexible carbon framework porosity manipulation at molecular level and would trigger further efforts for low-porosity carbons in energy storage.

A green and simple method to prepare metal/semiconductor nanocomposites by selective laser nano-welding metal and semiconductor nanoparticles was presented, in which the sizes, phases, and morphologies of the components can be maintained. Many types of nanocomposites (such as Ag/TiO2, Ag/SnO2, Ag/ZnO2, Pt/TiO2, Pt/SnO2, and Pt/ZnO) can be prepared by this method and their corresponding performances were enhanced.

Correction for ‘Preparation of carbon dots by non-focusing pulsed laser irradiation in toluene’ by Huiwu Yu et al., Chem. Commun., 2016, 52, 819–822, DOI: 10.1039/C5CC08384B.

The complex and serious spectral interference makes it difficult to detect trace elements in soil using laser-induced breakdown spectroscopy (LIBS). To address it, LIBS-assisted by laser-induced fluorescence (LIBS-LIF) was applied to selectively enhance the spectral intensities of the interfered lines. Utilizing this selective enhancement effect, all the interference lines could be eliminated. As an example, the Pb I 405.78 nm line was enhanced selectively. The results showed that the determination coefficient (R2) of calibration curve (Pb concentration range = 14-94 ppm), the relative standard deviation (RSD) of spectral intensities, and the limit of detection (LOD) for Pb element were improved from 0.6235 to 0.9802, 10.18% to 4.77%, and 24 ppm to 0.6 ppm using LIBS-LIF, respectively. These demonstrate that LIBS-LIF can eliminate spectral interference effectively and improve the ability of LIBS to detect trace heavy metals in soil.

To detect available heavy metals in soil using laser-induced breakdown spectroscopy (LIBS) and improve its poor detection sensitivity, a simple and low cost sample pretreatment method named solid-liquid-solid transformation was proposed. By this method, available heavy metals were extracted from soil through ultrasonic vibration and centrifuging and then deposited on a glass slide. Utilization of this solid-liquid-solid transformation method, available Cd and Pb elements in soil were detected successfully. The results show that the regression coefficients of calibration curves for soil analyses reach to more than 0.98. The limits of detection could reach to 0.067 and 0.94 ppm for available Cd and Pb elements in soil under optimized conditions, respectively, which are much better than those obtained by conventional LIBS.

Regulating the chemical/physical features of solution processed metal halide perovskite films by integrating sub-10 nm nanocrystals is a highly promising strategy to advance their outstanding optoelectronic performance. However, significant challenges remain for the universal embedding of the well-defined nanocrystals in the film matrix. By generating nanocrystals in desired solvents via pulsed laser irradiation in liquid, the authors demonstrate the effective decoration of sub-10 nm nanocrystals in perovskite films for enhanced optoelectronic performance. It is believed that this improved performance is due to the modification of the widely adopted "antisolvent" to a novel "anti-colloidal-solution" (ACS). Exemplified by a typical ACS; carbon dots in chlorobenzene, its encouraging superiority in regulating, not only the films morphology, but also the electronic structure, is demonstrated. This results in perovskite solar cells with a champion efficiency of 21.41% as well as a pronounced stability over 5000 h in relative humidity of 40%. The capability of nanocrystal embedding for boosted photovoltaic performance is further exploited by employing other laser generated ACSs. Such a strategy may open up a route to regulating hybrid perovskite film performance via nanocrystal embedding for photovoltaics or even beyond optoelectronic applications.

Control of the active sites/centers plays an important role in the design of novel electrode materials with unusual properties and achievement of sensors with high performance.

Addressing the intrinsic charge transport limitation of metal oxides has been of significance for pursuing viable PEC water splitting photoelectrodes. Growing a photoelectrode with conductive nanoobjects embedded in the matrix is promising for enhanced charge transport but remains a challenge technically. We herein show a strategy of embedding laser generated nanocrystals in BiVO 4 photoanode matrix, which achieves photocurrent densities of up to 5.15 mA cm −2 at 1.23 V RHE (from original 4.01 mA cm −2 ) for a single photoanode configuration, and 6.22 mA cm −2 at 1.23 V RHE for a dual configuration. The enhanced performance by such embedding is found universal owing to the typical features of laser synthesis and processing of colloids (LSPC) for producing ligand free nanocrystals in desired solvents. This study provides an alternative to address the slow bulk charge transport that bothers most metal oxides, and thus is significant for boosting their PEC water splitting performance.

In article number 1901341, Hongqiang Wang and co-workers report that a droplet of laser generated anti-colloidal-solution which contains ligand-free nanocrystals in a desired anti-solvent can effectively boost the charge transfer of the photogenerated carriers in perovskite solar cells, resulting in a power conversion efficiency of 21.41%, as well as a pronounced stability over 5000 h in relative humidity of 40%.

Polydopamine was used simultaneously as nitrogen-doped carbon precursors,adsorbent and reducing agent of CoCl2.Nitrogen and Co nanoparticles could be in situ doped and surface modified successively into/onto SiO2@C spheres,i.e.,SiO2@C/N-Co,via a facile and one-step calcination under nitrogen protection.The conductivity,electron transfer ability,and electrocatalytic activity of SiO2@C sphere were improved by the synergistic effect of surface modification with Co nanoparticles and nitrogen doping.The sensitivity of this electrochemical sensor was enhanced.Compared with SiO2@C/N,the oxidation peak current of SiO2@C/N-Co was increased from-39.17 μA to-119.4 μA for 100 μmol/L of catechol(CC) and from-24.0 μA to-110.8 μA for 100 μmol/L of hydroquinone(HQ).The sensitivity of SiO2@C/N-Co was improved 3.05 and 4.62 times for CC and HQ,respectively.Both CC and HQ could be detected simultaneously by SiO2@C/N-Co modified electrode with differential pulse voltammetry.With wide linear range(1.0-200 and 0.5-400 μmol/L for CC and HQ,respectively) and low detection limit(0.17 and 0.09 μmol/L for CC and HQ,respectively),this proposed method was successfully applied for simultaneous detection of CC and HQ in Jiulong River water.

Bulk g-C3N4 was transformed into water-soluble graphitic carbon nitride quantum dots (g-CNQDs) via a chemical oxidation and liquid exfoliation process. The g-CNQDs possess a size distribution ranging from 1 to 5 nm (centered at 3 nm), excellent crystallinity, and are water soluble. It is found that Fe(III) ions are adsorbed on the surface of the g-CNQDs via electrostatic interaction, and that the blue fluorescence of the g-CNQDs is reduced by Fe(III) via an inner filter effect. By using the g-CNQDs as a fluorescent probe, Fe(III) can be determined at excitation/emission wavelengths of 241/368 nm in spiked natural water samples within 1 min and with good selectivity over other ions. Response is linear in the 0.2–60 μmol·L−1 Fe(III) concentration range, and the detection limit is 23 nmol·L−1.

Through an ester-like bond,titanium dioxide(TiO2) nanoparticles were modified with benzoic acid(or/and phosphoric acid) by one-step chemisorption.The surface characteristics of TiO2 were improved,with negatively charge,hydrophilicity,hydrophobicity,and oxygen affinity.After irradiation with Xenon lamp for 2 h,the photodegradation ratio of TiO2 for Rhodamine B(as cationic dyes) was improved from 54.9％ to 71.5％,72.8％,91.2％ by the surface modification with the optimal dose of benzoic acid,phosphoric acid,benzoic acid and phosphoric acid,respectively.After surface comodification,the synergistic effect from oxygen affinity of phosphate groups and hydrophobicity of phenyl group could be used to overcome the major obstacles of heterogeneous photocatalysis,including the poor surface coverage of the pollutants on the catalyst and the rapid consumption of oxygen on the TiO2 surface.The photodegradation ratio was enough for the requirement of sample pretreatment for the determination of COD and TOC.