@article {46648, title = {Ultrahigh sensitive carbon-based conducting rubbers for flexible and wearable human-machine intelligence sensing}, journal = {Advanced Materials Technologies}, volume = {5}, year = {2020}, month = {DEC}, pages = {2000690}, type = {Article}, abstract = {

The wearable strain sensors with multifunctional applications can fuel the rapid development of human-machine intelligence for various sectors like healthcare, soft robotics, and Internet of Things applications. However, achieving the low-cost and mass production of wearable sensors with ultra-high performance remains challenging. Herein, a simple, cost-effective, and scalable methodology to fabricate the flexible and highly sensitive strain sensors using carbon black and latex rubbers (LR) is presented. The LR-based strain sensor demonstrates excellent flexibility, fast response (approximate to 600 ms), ultra-high sensitivity (maximum gauge factor of 1.2 x 10(4) at 250\% strain), and long-term stability over 1000 cycles. The LR-based strain sensors are sensitive to monitor subtle human motions such as heart pulse rate and voice recognition along with high-strain human joint operations. Additionally, the sensing mechanism of LR bands is investigated by surface topographies and electromechanical response under various strained/unstrained conditions. Further, a smart glove-based sensor module made of LR strain bands with an Arduino reader for the human-machine intelligence device for non-verbal communication in military applications is demonstrated.

}, keywords = {conducting rubbers, gauge factor, human\&\#8211, machine interfacing, voice recognition, wearable strain sensors}, issn = {2365-709X}, doi = {10.1002/admt.202000690, Early Access Date = NOV 2020}, author = {Ajeev, Arya and Javaregowda, Bharathkumar H. and Ali, Ashik and Modak, Mrudul and Patil, Shreya and Khatua, Saumyakanta and Ramadoss, Marimuthu and Kothavade, Premkumar Anil and Arulraj, Arul Kashmir} } @article {46731, title = {Unsymmetrical squaraine dyes for dye-sensitized solar cells: position of the anchoring group controls the orientation and self-assembly of sensitizers on the TiO2 surface and modulates its flat band potential}, journal = {Journal of Physical Chemistry C}, volume = {124}, year = {2020}, month = {AUG}, pages = {18436-18451}, type = {Article}, abstract = {

The position of the anchoring group is systematically changed with a series of alkyl group wrapped donor-acceptor-donor (D-A-D) based squaraine dyes, 4-SQ to 7-SQ, for the use in dye-sensitized solar cells (DSSCs). By this approach, the orientation as well as the self-assembly of the sensitizers can be controlled on the semiconducting TiO2 surface. All of the dyes functionalized with hydrophobic alkyl groups at sp(3)-C and N atoms of the indoline units that is far away from the TiO2 surface to control the self-assembly of dyes and passivate the surface. Controlling both the orientation as well as the self-assembly of the sensitizers synergistically enhances the V-oc of the DSSC device by imparting the dipole moment on the TiO2 surface and minimizing the interfacial charge recombination process of electrons from TiO2 to the oxidized electrolyte, respectively. Further, the presence of a meta-carboxyl group with respect to the N atom of the indoline donor unit for the dyes 4-SQ and 6-SQ makes them nonconductive for the charge injection process, which sheds light on the importance of through-space electron transfer for the device performance. Emission from the relaxed twisted state was found to be a deactivation pathway for 4-SQ on TiO2 and ZrO2, which revealed the importance of structural factors that promote spatial interaction between the sensitizer and metal oxide surface. Computational studies showed the systematic changes in the dipole moment for the sensitizers 4-SQ, 5-SQ, and 6-SQ upon anchoring to the TiO2 surface. The DSSC device performance varied with the position of anchoring groups in the sensitizers. The DSSC device performance of 5-SQ indicates a J(sc) value of 11.35 mA cm(-2), V-oc of 0.698 V, and ff of 77\% corresponding to a power conversion efficiency of 6.08\% in the presence of 3 equiv of coadsorbent CDCA, which is nearly 1.5 times higher than 6-SQ (V-oc 0.7 V, J(sc) 7.76 mA cm(-2), ff 76\%, and eta 4.14\%) and 2.6 times higher than 4-SQ (V-oc 0.658 V, J(sc) 4.42 mA cm(-2), ff 78\%, and eta 2.28\%). IPCE studies revealed the importance of orientation for the charge injection and self-assembly of dyes, as devices with 5-SQ and 6-SQ as a sensitizer showed 94 and 77\% response at 578 nm, respectively, which correspond to the aggregated structure of the dye. Mott-Schottky and IPCE experiments showed that the orientation of sensitizers could modulate the V-oc due to the shift in the flat band potential of TiO2.

}, issn = {1932-7447}, doi = {10.1021/acs.jpcc.0c05176}, author = {Singh, Ambarish Kumar and Maibam, Ashakiran and Javaregowda, Bharathkumar H. and Bisht, Rajesh and Kudlu, Ashwath and Krishnamurty, Sailaja and Krishnamoorthy, Kothandam and Nithyanandhan, Jayaraj} } @article {49844, title = {Utilizing nature{\textquoteright}s endowment: artificial leaf concept for methane activation to C-C coupled ethanol or ethylene}, journal = {Sustainable Energy \& Fuels}, volume = {9}, year = {2025}, month = {DEC}, pages = {6798-6810}, type = {Article}, abstract = {

Methane activation (MA) to platform chemicals under ambient conditions still remains an open challenge to be fully realised. The present work shows the fabrication of CeVO4 quantum dots (CV-QDs) by a bottom-up approach; they are assembled from Ce3+ and metavanadate ions, and structurally and electronically integrated into the micro-/meso-pores of TiO2 (CV-QD-TiO2 (CVT)), demonstrating the conversion of MA to ethanol/ethylene by visible light-driven photocatalysis. CV-QDs in confined pores modify the quantum confinement effects and are characterized by physicochemical methods. The current synthetic strategy is potentially scalable and results in sub-quadrillion heterojunctions in a 1 mg CVT photoanode spread over 1 cm2. MA with CVT under one-sun conditions demonstrates similar to 100\% selectivity to ethanol, yielding 4.36 mu mol h-1 cm-2, with a solar-to-fuel efficiency (STFE) of 0.56. Further, by employing a co-catalyst, significant STFE (5.08) and yield (39.5 mu mol h-1 cm-2) are achieved selectively towards ethylene. A deliberate addition of methanol increases the rate of ethanol production by 17.2 times, indicating that the methyl-methoxy interaction is the origin of C-C coupling. Weight is normalized to a gram of CV-QDs in a large area CVT photoanode to yield 109 mmol h-1 gCV-QD-1 of ethanol and 988 mmol h-1 gCV-QD-1 of ethylene. Enhanced activity and selectivity towards the C2-product is attributed to band-edge modulation and trillions of heterojunctions, which in turn facilitate charge separation and charge transfer for effective charge utilisation at redox sites.

}, issn = {2398-4902}, doi = {10.1039/d5se01178g}, author = {Kanungo, Subhashree S. and Mishra, Abhaya Kumar and Avani, Mangaladasan J. and Bajpai, Himanshu and Salgaonkar, Kranti N. and Javaregowda, Bharathkumar H. and Gopinath, Chinnakonda S.} }