Sustainable microalgae extraction for proactive water bloom prevention

Statistical Source Dat

In situ dissolution-diffusion toward homogeneous multiphase Ag/Ag2S@ZnS core-shell heterostructures for enhanced photocatalytic performance

10.1021/jp510413bJournal of Physical Chemistry C11941667-167

Self-Biased Hybrid Piezoelectric-Photoelectrochemical Cell with Photocatalytic Functionalities

Utilizing solar energy for environmental and energy remediations based on photocatalytic hydrogen (H₂) generation and water cleaning poses great challenges due to inadequate visible-light power conversion, high recombination rate, and intermittent availability of solar energy. Here, we report an energy-harvesting technology that utilizes multiple energy sources for development of sustainable operation of dual photocatalytic reactions. The fabricated hybrid cell combines energy harvesting from light and vibration to run a power-free photocatalytic process that exploits novel metal–semiconductor branched heterostructure (BHS) of its visible light absorption, high charge-separation efficiency, and piezoelectric properties to overcome the aforementioned challenges. The desirable characteristics of conductive flexible piezoelectrode in conjunction with pronounced light scattering of hierarchical structure originate intrinsically from the elaborate design yet facile synthesis of BHS. This self-powered photocatalysis system could potentially be used as H₂ generator and water treatment system to produce clean energy and water resources

Atomic- and Molecular-Level Design of Functional Metal-Organic Frameworks (MOFs) and Derivatives for Energy and Environmental Applications

10.1002/advs.201901129ADVANCED SCIENCE62

Room temperature sequential ionic deposition (SID) of Ag2S nanoparticles on TiO2 hierarchical spheres for enhanced catalytic efficiency

10.1039/c4ta06674jJournal of Materials Chemistry A3126509-651

Device Stability and Light-Soaking Characteristics of High-Efficiency Benzodithiophene–Thienothiophene Copolymer-Based Inverted Organic Solar Cells with F‑TiO_<i>x</i> Electron-Transport Layer

Organic solar cells (OSC) based on low-band-gap thienothiophene–benzodithiophene copolymer have achieved relatively high efficiency (7–9%) in recent times. Among this class of material, poly­({4,8-bis­[(2-ethylhexyl)­oxy]­benzo­[1,2-b:4,5-b′]­dithiophene-2,6-diyl}­{3-fluoro-2-[(2-ethylhexyl)­carbonyl]­thieno­[3,4-<i>b</i>]­thiophenediyl}) (PTB-7) is one of the high-efficiency materials reported for OSC. However, this material seems to be intrinsically unstable compared to the commonly used workhorse polymer, poly­(3-hexylthiophene) (P3HT), especially when illuminated in air. Inverted device architecture is usually adopted to improve device stability, but the device stability using PTB-7 is not yet well-understood. In this work, a systematic degradation study on a PTB-7:PC₇₁BM-based inverted OSC employing F-TiO_<i>x</i> as electron-transport layer (ETL) was conducted for the first time. Air stability, photostability in inert atmosphere, and photostability under ambient conditions of the device were separately carried out to understand better the polymer behavior in inverted OSC. The device’s air stability with different polymer absorber layers was studied by exposing the devices in air for up to 1500 h. Because of the long and easily cleavable alkoxy side chains in the polymer backbone, a PTB-7:PC₇₁BM-based inverted OSC device is highly susceptible to oxygen and moisture when compared to a P3HT:PC₆₁BM-based device. In addition, with the presence of F-TiO_<i>x</i> ETL, a significant reduction in light-soaking time was also observed in PTB-7:PC₇₁BM inverted OSC for the first time. The TiO_<i>x</i>/organic interface was found to be responsible for the reduction in the light-soaking time

Addressing the light-soaking issue in inverted organic solar cells using chemical bath deposited fluorinated TiOx electron transport layer

10.1039/c4ta05042hJournal of Materials Chemistry A31314-32

Resistive Switching and Polarization Reversal of Hydrothermal-Method-Grown Undoped Zinc Oxide Nanorods by Using Scanning Probe Microscopy Techniques

This paper reports the localized electrical, polarization reversal, and piezoelectric properties of the individual hexagonal ZnO nanorods, which are grown via the hydrothermal method and textured with [0001] orientation. The studies are conducted with conductive atomic force microscopy (c-AFM) and piezoresponse force microscopy (PFM) techniques. The correlation between the resistance switching and polarization reversal is discussed. The c-AFM results show that there is less variation on the set or reset voltage in nanorod samples, compared to that of the ZnO thin film. With increasing aspect ratio of the nanorods, both set and reset voltages are decreased. The nanorods with low aspect ratio show unipolar resistance switching, whereas both unipolar and bipolar resistance switching are observed when the aspect ratio is larger than 0.26. The PFM results further show the ferroelectric-like property in the nanorods. Comparing with that of the ZnO thin film, the enhanced piezoresponse in the nanorods can be attributed to the size effect. In addition, the piezoresponse force spectroscopy (PFS) experiments are conducted in ambient air, synthetic air, and argon gas. It shows that the depolarization field in the nanorod may be due to the moisture in the environment; moreover, the increased piezoresponse may relate to the absence of oxygen in the environment. It is also shown that the piezoelectric responses increase nonlinearly with the aspect ratio of the nanorods. By comparing the piezoresponse hysteresis loops obtained from the nanorod samples of as-grown, air-annealed and vacuum-annealed, it is found that the oxygen vacancies are the origin of the polarization reversal in ZnO nanorods. Finally, the tradeoff between the electrical and ferroelectric-like properties is also observed

A 0.14 pJ/conversion Fully Energy-Autonomous Temperature-to-Time Converter for Biomedical Applications

We present a fully energy-autonomous temperature-to-time converter (TTC) for biomedical applications. This is the first work in literature to power the entire converter purely by a triboelectric energy harvester (TEG). The dynamic leakage suppression full-bridge rectifier (DLS-FBR) reduces reverse leakage current to 1/100, which enables the TEG operated by human motion at &lt;1 Hz as a sole power source; once the harvested voltage reaches 0.6 V, the one-shot TTC converts the temperature into pulse width, measuring a temperature range of 15 degrees C-45 degrees C. The TTC in 0.18-mu m 1P6M CMOS consumes 0.14 pJ/conversion while powered up purely by a TEG, achieving energy-autonomous operation.N