High-Pressure Electro-Fenton Driving CH4 Conversion by O2 at Room Temperature.

Electrochemical conversion of CH4 to easily transportable and value-added liquid fuels is highly attractive for energy-efficient CH4 utilization, but it is challenging due to the low reactivity and solubility of CH4 in the electrolyte. Herein, we report a high-pressure electro-Fenton (HPEF) strategy to establish a hetero-homogeneous process for the electrocatalytic conversion of CH4 by O2 at room temperature. In combination with elevation of reactant pressure to accelerate reaction kinetics, it delivers an unprecedented HCOOH productivity of 11.5 mmol h-1 gFe-1 with 220 times enhancement compared to that under ambient pressure. Remarkably, an HCOOH Faradic efficiency of 81.4% can be achieved with an ultralow cathodic overpotential of 0.38 V. The elevated pressure not only promotes the electrocatalytic reduction of O2 to H2O2 but also increases the reaction collision probability between CH4 and •OH, which is in situ generated from the Fe2+-facilitated decomposition of H2O2.

Full-Spectrum Light-Harvesting Solar Thermal Electrocatalyst Boosts Oxygen Evolution.

Enabling high-efficiency solar thermal conversion (STC) at catalytic active site is critical but challenging for harnessing solar energy to boost catalytic reactions. Herein, we report the direct integration of full-spectrum STC and high electrocatalytic oxygen evolution activity by fabricating a hierarchical nanocage architecture composed of graphene-encapsulated CoNi nanoparticle. This catalyst exhibits a near-complete 98 % absorptivity of solar spectrum and a high STC efficiency of 97 %, which is superior than previous solar thermal catalytic materials. It delivers a remarkable potential decrease of over 240 mV at various current densities for electrocatalytic oxygen evolution under solar illumination, which is practically unachievable via traditionally heating the system. The high-efficiency STC is enabled by a synergy between the regulated electronic structure of graphene via CoNi-carbon interaction and the multiple absorption of lights by the light-trapping nanocage. Theoretical calculations suggest that high temperature-induced vibrational free energy gain promotes the potential-limiting *O to *OOH step, which decreases the overpotential for oxygen evolution.

Geometric effect of Au nanoclusters on room temperature CO oxidation.

We report the effect of in situ transforming ZnO supported single Au atoms to 3-dimensional Au clusters (Au3D) on room temperature CO oxidation activity. We discovered that an intermediate, highly distorted 2-dimensional Au layer species is much more active than both the Au3D clusters and the Au single atoms. The geometric arrangement of Au clusters and their interactions with support surfaces play a pivotal role in determining their catalytic performance in room temperature CO oxidation on ZnO supported Au catalysts.

Double-Channel Piezotronic Transistors for Highly Sensitive Pressure Sensing.

Piezotronic transistors (PTs) that utilize inner crystal potential generated by interface piezoelectric polarization charges as the gate voltage have great potential applications in force/pressure-triggered or controlled electronic devices, sensors, human-machine communication, and microelectromechanical systems. Although the performance of PTs has been partially enhanced by exploring special materials with different geometries or high piezoelectricity, few studies have been focused on the structure design of PT itself to more effectively enhance the performance and structural reliability. Here, an integrated double-channel plane piezotronic transistor is invented as a high-performance pressure-sensing technology. Owing to the double-channel modulation and the plane structure, the PT has the merits of high pressure sensitivity (84.2-104.4 meV/MPa) and high structural reliability, which provides the opportunity for great applications, such as human-computer interfacing, biosensing, and health monitoring.