Abstract
By electronically wiring-up living cells with abiotic conductive surfaces, bioelectrochemical systems (BES) harvest energy and synthesize electric-/solar-chemicals with unmatched ...thermodynamic efficiency. However, the establishment of an efficient electronic interface between living cells and abiotic surfaces is hindered due to the requirement of extremely close contact and high interfacial area, which is quite challenging for cell and material engineering. Herein, we propose a new concept of a single cell electron collector, which is
in-situ
built with an interconnected intact conductive layer on and cross the individual cell membrane. The single cell electron collector forms intimate contact with the cellular electron transfer machinery and maximizes the interfacial area, achieving record-high interfacial electron transfer efficiency and BES performance. Thus, this single cell electron collector provides a superior tool to wire living cells with abiotic surfaces at the single-cell level and adds new dimensions for abiotic/biotic interface engineering.
The general synthesis and control of the coordination environment of single‐atom catalysts (SACs) remains a great challenge. Herein, a general host–guest cooperative protection strategy has been ...developed to construct SACs by introducing polypyrrole (PPy) into a bimetallic metal–organic framework. As an example, the introduction of Mg2+ in MgNi‐MOF‐74 extends the distance between adjacent Ni atoms; the PPy guests serve as N source to stabilize the isolated Ni atoms during pyrolysis. As a result, a series of single‐atom Ni catalysts (named NiSA‐Nx‐C) with different N coordination numbers have been fabricated by controlling the pyrolysis temperature. Significantly, the NiSA‐N2‐C catalyst, with the lowest N coordination number, achieves high CO Faradaic efficiency (98 %) and turnover frequency (1622 h−1), far superior to those of NiSA‐N3‐C and NiSA‐N4‐C, in electrocatalytic CO2 reduction. Theoretical calculations reveal that the low N coordination number of single‐atom Ni sites in NiSA‐N2‐C is favorable to the formation of COOH* intermediate and thus accounts for its superior activity.
A host–guest cooperative protection strategy has been developed for constructing single‐atom catalysts (SACs), extending the range of available precursors from nitrogenous to non‐nitrogenous MOFs. The obtained Ni‐SACs (NiSA‐Nx‐C; x=2, 3, 4) at different pyrolysis temperatures feature varying nitrogen coordination numbers. The best of these catalysts, NiSA‐N2‐C, shows superior activity and selectivity in CO2 electroreduction.
A Li3PO4 solid electrolyte interphase (SEI) layer is demonstrated to be stable in the organic electrolyte, even during the Li deposition/dissolution process. Thus, the Li‐conducting Li3PO4 SEI layer ...with a high Young's modulus can effectively reduce side reactions between Li metal and the electrolyte and can restrain Li dendrite growth in lithium‐metal batteries during cycling.
Low extracellular electron transfer performance is often a bottleneck in developing high‐performance bioelectrochemical systems. Herein, we show that the self‐assembly of graphene oxide and ...Shewanella oneidensis MR‐1 formed an electroactive, reduced‐graphene‐oxide‐hybridized, three‐dimensional macroporous biofilm, which enabled highly efficient bidirectional electron transfers between Shewanella and electrodes owing to high biomass incorporation and enhanced direct contact‐based extracellular electron transfer. This 3D electroactive biofilm delivered a 25‐fold increase in the outward current (oxidation current, electron flux from bacteria to electrodes) and 74‐fold increase in the inward current (reduction current, electron flux from electrodes to bacteria) over that of the naturally occurring biofilms.
Shocking bacteria! The title biofilm was constructed by the one‐step in situ bioreduction and self‐assembly of graphene oxide (GO) with Shewanella oneidensis. The resulting 3D macroporous rGO/bacteria hybrid biofilm gave a 25‐fold increase in maximum oxidation current in microbial fuel cells, and a 74‐fold increase in reduction current in microbial electrosynthesis over that of the naturally occurring biofilms.
The Li metal anode has long been considered as one of the most ideal anodes due to its high energy density. However, safety concerns, low efficiency, and huge volume change are severe hurdles to the ...practical application of Li metal anodes, especially in the case of high areal capacity. Here it is shown that that graphitized carbon fibers (GCF) electrode can serve as a multifunctional 3D current collector to enhance the Li storage capacity. The GCF electrode can store a huge amount of Li via intercalation and electrodeposition reactions. The as‐obtained anode can deliver an areal capacity as high as 8 mA h cm−2 and exhibits no obvious dendritic formation. In addition, the enlarged surface area and porous framework of the GCF electrode result in lower local current density and mitigate high volume change during cycling. Thus, the Li composite anode displays low voltage hysteresis, high plating/stripping efficiency, and long lifespan. The multifunctional 3D current collector promisingly provides a new strategy for promoting the cycling lifespan of high areal capacity Li anodes.
Graphitized carbon fiber electrode is demonstrated to improve the cycling performance of high‐areal‐capacity Li anodes due to dual reaction types, reduced current density, and confined volume change. This Li anode can deliver a high areal capacity of 8 mA h cm−2 without Li dendrites and displays low voltage hysteresis, high plating/stripping efficiency, and long cycling lifespan.
Nanotechnology has become one of the most promising technologies applied in all areas of science. Metal nanoparticles produced by nanotechnology have received global attention due to their extensive ...applications in the biomedical and physiochemical fields. Recently, synthesizing metal nanoparticles using microorganisms and plants has been extensively studied and has been recognized as a green and efficient way for further exploiting microorganisms as convenient nanofactories. Here, we explore and detail the potential uses of various biological sources for nanoparticle synthesis and the application of those nanoparticles. Furthermore, we highlight recent milestones achieved for the biogenic synthesis of nanoparticles by controlling critical parameters, including the choice of biological source, incubation period, pH, and temperature.
Microbial electrocatalysis systems (MES) provide a cutting‐edge solution to global problems associated with the environment and energy, but practical applications are hindered by the expensive ...electrode materials. Although stainless steel (SS) has been proposed as a promising inexpensive candidate, poor cell/SS interaction results in a low performance for MES. Here, a new synthetic biology approach was established for reinforcing the cell/SS interaction. Hybridized curli nanofibers fused with a metal‐binding domain were heterogeneously expressed onto the cell surface, which realized efficient cell binding with the SS electrode. Consequently, it enabled a ~420‐fold improvement of the anodic power output and a substantial enhancement of the cathodic Coulombic efficiency (from 0.6 to 4% to over 80%) with an SS electrode. This work demonstrates low‐cost MES with an SS electrode and introduces a new avenue to engineer the cell/electrode interaction, which is promising for future practical applications of MES.
Hybrid sp2 carbon with a graphene backbone and graphitic carbon nanocages (G‐GCNs) is demonstrated as an ideal host for sulfur in Li–S batteries, because it serves as highly efficient electrochemical ...nanoreactors as well as polysulfides reservoirs. The as‐obtained S/(G‐GCNs) with high S content exhibits superior high‐rate capability (765 mA h g−1 at 5 C) and long‐cycle life over 1000 cycles.
A subzero‐temperature cathode material is obtained by nucleating cubic prussian blue crystals at inhomogeneities in carbon nanotubes. Due to fast ionic/electronic transport kinetics even at −25 °C, ...the cathode shows an outstanding low‐temperature performance in terms of specific energy, high‐rate capability, and cycle life, providing a practical sodium‐ion battery powering an electric vehicle in frigid regions.
Selenium has been confined in the form of cyclic Se8 molecules within ordered mesoporous carbon for use as a cathode material in Li–Se batteries. An ex situ study of the Se cathode reveals conversion ...from cyclic Se8 molecules into chain‐like Sen molecules upon cycling. This effectively eliminates the shuttle effect of Se, resulting in superior electrochemical performance in terms of volumetric capacity density and cycling stability.
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