High-Throughput Bubble Screening Method for Combinatorial Discovery of Electrocatalysts for Water Splitting

Combinatorial synthesis and screening for discovery of electrocatalysts has received increasing attention, particularly for energy-related technologies. High-throughput discovery strategies typically employ a fast, reliable initial screening technique that is able to identify active catalyst composition regions. Traditional electrochemical characterization via current–voltage measurements is inherently throughput-limited, as such measurements are most readily performed by serial screening. Parallel screening methods can yield much higher throughput and generally require the use of an indirect measurement of catalytic activity. In a water-splitting reaction, the change of local pH or the presence of oxygen and hydrogen in the solution can be utilized for parallel screening of active electrocatalysts. Previously reported techniques for measuring these signals typically function in a narrow pH range and are not suitable for both strong acidic and basic environments. A simple approach to screen the electrocatalytic activities by imaging the oxygen and hydrogen bubbles produced by the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is reported here. A custom built electrochemical cell was employed to record the bubble evolution during the screening, where the testing materials were subject to desired electrochemical potentials. The transient of the bubble intensity obtained from the screening was quantitatively analyzed to yield a bubble figure of merit (FOM) that represents the reaction rate. Active catalysts in a pseudoternary material library, (Ni–Fe–Co)O_x, which contains 231 unique compositions, were identified in less than one minute using the bubble screening method. An independent, serial screening method on the same material library exhibited excellent agreement with the parallel bubble screening. This general approach is highly parallel and is independent of solution pH

Comparison of the analgesic properties of cucumis melo seeds extract and ibuprofen on Wistar albino rats rattus novegicus albinus via hot-plate test

This study was done to compare the analgesic properties of cucumis melo (CM) seeds oil extract against ibuprofen on rattus norvegicus albinus (Wistar Albino rats) using hot-plate test. Oil extraction was made by utilizing a soxhlet apparatus maintained under 60-70 C for five hours using 80% methanol. Randomization of the three groups was done via drawlots procedure and drugs were administered via syringe feeding. The analgesic properties of CM and ibuprofen were evaluated via Hot-plate test. Onset of pain and the pain tolerance were noted by observing the rats\u27 paw-licking and jumping out of the beaker, respectively. CM group showed the longest time before pain onset, with a mean reaction time of 16.74 seconds. As for pain tolerance, the Ibuprofen group held the longest time with a mean reaction time of 8.69 seconds. Pain threshold (H-1.87, P=.039) and pain tolerance (H=3.29, P=0.193) results showed that there was no statistically significant difference among the analgesic effect of CM and Ibuprofen

High-Throughput Bubble Screening Method for Combinatorial Discovery of Electrocatalysts for Water Splitting

Combinatorial synthesis and screening for discovery of electrocatalysts has received increasing attention, particularly for energy-related technologies. High-throughput discovery strategies typically employ a fast, reliable initial screening technique that is able to identify active catalyst composition regions. Traditional electrochemical characterization via current–voltage measurements is inherently throughput-limited, as such measurements are most readily performed by serial screening. Parallel screening methods can yield much higher throughput and generally require the use of an indirect measurement of catalytic activity. In a water-splitting reaction, the change of local pH or the presence of oxygen and hydrogen in the solution can be utilized for parallel screening of active electrocatalysts. Previously reported techniques for measuring these signals typically function in a narrow pH range and are not suitable for both strong acidic and basic environments. A simple approach to screen the electrocatalytic activities by imaging the oxygen and hydrogen bubbles produced by the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is reported here. A custom built electrochemical cell was employed to record the bubble evolution during the screening, where the testing materials were subject to desired electrochemical potentials. The transient of the bubble intensity obtained from the screening was quantitatively analyzed to yield a bubble figure of merit (FOM) that represents the reaction rate. Active catalysts in a pseudoternary material library, (Ni–Fe–Co)­O_<i>x</i>, which contains 231 unique compositions, were identified in less than one minute using the bubble screening method. An independent, serial screening method on the same material library exhibited excellent agreement with the parallel bubble screening. This general approach is highly parallel and is independent of solution pH