Seeking a simple and moderate route to generate reactive oxygen species (ROS) for antibiosis is of great interest and challenge. This work demonstrates that molecule transition and electron rearrangement processes can directly occur only through chemisorption interaction between the adsorbed O and high-energy {111} facet-exposed MgO with abundant surface oxygen vacancies (SOVs), hence producing singlet oxygen and superoxide anion radicals without light irradiation. These ROS were confirmed by electron paramagnetic resonance, in situ Raman, and scavenger experiments. Furthermore, heat plays a crucial role for the electron transfer process to accelerate the formation of ·O, which is verified by temperature kinetic experiments of nitro blue tetrazolium reduction in the dark. Therefore, the presence of oxygen vacancy can be considered as an intensification of the activation process. The designed MgO is acquired in one step via constructing a reduction atmosphere during the combustion reaction process, which has an ability similar to that of noble metal Pd to activate molecular oxygen and can be used as an effective bacteriocide in the dark.

A glucose/O2 biofuel cell (BFC) possessing a pH-dependent power output was fabricated by taking porous carbon (PC) as the matrix to load glucose oxidase or fungi laccase as the catalysts. The electrolytes in the anode and cathode compartments contain ferrocene monocarboxylic acid and 2,2'-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) diammonium salt as the mediators, respectively. The power of the BFC was enhanced significantly by using PC as the matrix, rather than glassy carbon electrode. Additionally, the power output of the BFC decreases as the pH of the solution increases from 4.0 to 7.0, which provides a simple and efficient method to achieve the required power output. More importantly, the BFC can operate at pH 6.0, and even at pH 7.0, which overcomes the requirement for cathode solutions of pH<5.0 when using fungi laccase as a catalyst. Operation of the BFC at neutral pH may provide a means to power medical devices implanted in physiological systems. The facile and low-cost fabrication of this BFC may enable its development for other applications.

Nanostructured tin oxide thin films with columnar grains were deposited on gold-coated silicon substrates using the combustion chemical vapor deposition method. Microscopy revealed that the columnar grains were covered by nanoparticles of less than 20 nm. The electrochemical behavior of the as-prepared thin film electrodes was examined against a lithium counter electrode. These thin film electrodes exhibited high specific capacity and good capacity retention. The capacity increased from an initial value of about 353 (μA h)/(cm2 μm) gradually to a maximum value of ∼490 (μA h)/(cm2 μm) during cycling. The reversible capacity was about 460 (μA h)/(cm2 μm) after 80 cycles at a charge/discharge rate of 0.3 mA/cm2. When the electrodes were discharged at 0.9 mA/cm2, the capacity retention obtained was about 64% of the capacity at 0.3 mA/cm2. The good electrochemical performance is attributed to the unique nanostructure with longitudinal and radial connectivity of active materials.

We describe the use of an amphiphilic macromolecular brush based on poly(ethylene glycol) (PEG) and poly(D,L-lactide) (PLA) as a stabilizer of hydrophobic solutes. The brush, which in solution adopted an extended backbone conformation consequent with excluded volume effects of the side chains, retained an elongated character in water following the hydrophobic collapse of PLA and the backbone triggered by a rapid change in solvent quality. However, in the presence of hydrophobic solutes at low concentrations in a homogeneous environment, the brush formed spherical unimolecular nanoparticles achieving high solute encapsulation efficiency. As solute content increased and exceeded what appears to be a limit for intramolecular solubilization, intermolecular assembly took place along with the formation of large aggregates, the properties of which were highly dependent on the solute. This first observation of the solute-triggered unimolecular collapse of an amphiphilic macromolecular brush should find important applications for the design of polymeric drug carriers whose properties can be conveniently modified at the single molecule level.