Tuning of Reciprocal Carbon‐Electrode Properties for an Optimized Hydrogen Evolution.

Abstract

Closing the material cycle for harmful and rare resources is a key criterion for sustainable and green energy systems. The concept of using scalable biomass‐derived carbon electrodes to produce hydrogen from water was proposed here, satisfying the need for sustainability in the field of chemical energy conversion. The carbon electrodes exhibited not only water oxidation activity but also a strong self‐oxidation when being used as anode for water splitting. The carbon oxidation, which is more energy‐favorable, was intentionally allowed to occur for an improvement of the total current, thus enhancing the hydrogen production on the cathode side. By introducing different earth‐abundant metals, the electrode could be well adjusted to achieve an optimized water/carbon oxidation ratio and an appreciable reactivity for practical applications. This promising methodology may become a very large driver for carbon chemistry when waste organic materials or biomass can be converted using its intrinsic energy content of carbon. Such a process could open a safe path for sub‐zero CO2 emission control. The concept of how and which parameter of a carbon‐based electrode can be optimized was presented and discussed in this paper.

High Salt Electrolyte Solutions Challenge the Electrochemical CO2 Reduction Reaction to Formate at Indium and Tin Cathodes

“…When 50 mM NaHCO 3 buffer or 7 % NaCl MM63 V medium was provided, no formate production was monitored at the bare graphite. All charge was spent on HER, as expected for a carbon‐based electrode with the applied potential more negative than −0.8 V [57] . Therefore, it was hypothesized that selectivity shift towards HER from eCO 2 RR to formate at the In as well as Sn cathodes could be due to electrocatalyst loss from the graphite electrode surface.…”

“…When 50 mM NaHCO 3 buffer or 7 % NaCl MM63 V medium was provided, no formate production was monitored at the bare graphite. All charge was spent on HER, as expected for a carbon-based electrode with the applied potential more negative than À 0.8 V. [57] Therefore, it was hypothesized that selectivity shift towards HER from eCO 2 RR to formate at the In as well as Sn cathodes could be due to electrocatalyst loss from the graphite electrode surface. At the end of the experiments conducted under high salinity conditions (� 3 % NaCl) for 1 h, the uniform electrocatalyst coating on the graphite surface (Figure S1) visually seemed to be no longer present, confirming the potential electrocatalyst loss.…”

Metal‐Free Catalytic Reduction of 4‐Nitrophenol to 4‐Aminophenol by sp3@sp2‐Hybridized Bucky Nanodiamond

“…While in the oxidation process, the oxidation of the carbon surface normally happens to get newly formed oxygen functionalities. [ 32,33 ]…”

“…While in the oxidation process, the oxidation of the carbon surface normally happens to get newly formed oxygen functionalities. [32,33] In summary, the core-shell sp 3 @sp 2 -hybridized ND-600, ND-900, and ND-1100 are prepared by annealing NDs at 600, 900, and 1100 °C, respectively. The structural transformation and the change of the surface oxygen groups are studied systematically.…”

Controlled Self‐Assembly of Hollow Core‐Shell FeMn/CoNi Prussian Blue Analogs with Boosted Electrocatalytic Activity

“…The ECSA of the catalysts was calculated by the ratio of C dl to C s , while the double-layer capacitance was derived from the average absolute slope and the general specific capacitance of 40 µF cm -2 was used. [42,43] The Faradaic efficient (FE) was estimated under a constant current density of 100 mA cm −2 . The chronopotentiometric measurement for OER with FeMn@CoNi-H/NF electrode (FeMn@CoNi-H coated on Ni foam, 1 × 1 cm 2 ) was performed at 300 mA cm -2 for 40 h.…”