Electrochemical Sensing Platform Integrated with Solid-state Reference Electrode Based on Indium Tin Oxide Interdigitated Array Electrodes

We present a new strategy for the fabrication of a fully integrated electrochemical platform. The three-electrode system consists of an indium tin oxide interdigitated array as working electrode, a solid-state reference electrode, and an electrodeposited Pt counter electrode that are placed in microfluidic channel. By controlling the electrodeposition conditions, such as the applied potential and time, the stability and uniformity of the films can be optimized. A solid-state reference electrode was fabricated on the nanoporous Pt via electropolymerization of poly-1,3-phenylenediamine. This system provides a simple method for the fabrication of three-electrode system and opens the possibility for an electroanalytical platform.     

Synergic Electron and Defect Compensation Minimizes Voltage Loss in Lead-Free Perovskite Solar Cells

Sn perovskite solar cells have been regarded as one of the most promising alternatives to the Pb-based counterparts due to their low toxicity and excellent optoelectronic properties. However, the Sn perovskites are notorious to feature heavy p-doping characteristics and possess abundant vacancy defects, which result in under-optimized interfacial energy level alignment and severe nonradiative recombination. Here, we reported a synergic “electron and defect compensation” strategy to simultaneously modulate the electronic structures and defect profiles of Sn perovskites via incorporating a traced amount (0.1 mol %) of heterovalent metal halide salts. Consequently, the doping level of modified Sn perovskites was altered from heavy p-type to weak p-type (i.e. up-shifting the Fermi level by ∼0.12 eV) that determinately reducing the barrier of interfacial charge extraction and effectively suppressing the charge recombination loss throughout the bulk perovskite film and at relevant interfaces. Pioneeringly, the resultant device modified with electron and defect compensation realized a champion efficiency of 14.02 %, which is ∼46 % higher than that of control device (9.56 %). Notably, a record-high photovoltage of 1.013 V was attained, corresponding to the lowest voltage deficit of 0.38 eV reported to date, and narrowing the gap with Pb-based analogues (∼0.30 V).     

Organocatalytic Upgrading of Biomass Derived Building Blocks

The depletion of finite primary fossil fuels we are facing makes necessary a deep metamorphosis in fundamental parts of the chemical industry. A progressive transition from petro-based starting materials toward renewable biomass-derived sources will have to take place in the synthesis of added-value chemicals, important for our everyday life, such as pharmaceuticals, polymers, agrochemicals etc. Moreover, greener processes, carried out under friendlier reaction conditions, must be designed to address current concerns about the climate change and the resulting pressing need to reduce the environmental footprint of chemical processes. To this end, organocatalysis could offer a valuable opportunity for upgrading biomass-derived platform molecules in line with the principles of Green Chemistry. This review presents some of recent and remarkable advancements in this emerging area. Organocatalysis has proven to be an efficient tool to transform low value bio-based renewable platform building blocks into new high value bio-based chemicals, with potential applications as synthetic intermediates, innovative materials and pharmaceutically active compounds.     

Enhancing Carrier Transport via σ-Linkage Length Modulation in D-σ-A Semiconductors for Photocatalytic Oxidation

Carrier transport is an equally decisive factor as carrier separation for elevating photocatalytic efficiency. However, limited by indefinite structures and low crystallinities, studies on enhancing carrier transport of organic photocatalysts are still in their infancy. Here, we develop an σ-linkage length modulation strategy to enhance carrier transport in imidazole-alkyl-perylene diimide (IMZ-alkyl-PDI, corresponding to D-σ-A) photocatalysts by controlling π–π stacking distance. Ethyl-linkage can shorten π–π stacking distance (3.19 Å) the most among IMZ-alkyl-PDIs (where alkyl=none, ethyl, and n-propyl) via minimizing steric hindrance between D and A moieties, which leads to the fastest carrier transport rates. Thereby, IMZ-ethyl-PDI exhibits remarkable enhancement in phenol degradation with 32-fold higher rates than IMZ-PDI, as well as the oxygen evolution rate (271-fold increased). In microchannel reactors, IMZ-ethyl-PDI also presents 81.5 % phenol removal with high-flux surface hydraulic loading (44.73 L m⁻² h⁻¹). Our findings provide a promising molecular design guideline for high-performance photocatalysts and elucidate crucial internal carrier transport mechanisms.