centuries-old Haber-Bosch process that suffers from operating under harsh reaction conditions (400-500 °C, 200-250 bar) and needs natural gas as the hydrogen source. [7,8] Therefore, it is highly desired to develop less energy-demanding approaches for sustainable N 2 -to-NH 3 fixation.In biological synthetic processes, certain bacteria are able to convert N 2 into NH 3 with the help of fascinating enzymes under mild conditions. [9][10][11] Electrocatalytic NH 3 synthesis using water as the hydrogen source has been proposed as a sustainable process to make NH 3 at ambient conditions. [12,13] The less abundance and high cost of N 2 reduction reaction (NRR) electrocatalysts based on precious metals (Au, [14,15] Rh, [16] Pd, [17] Ru, [18] and Ag [19] ) push the researchers to explore nonnoble metal alternatives. [20][21][22][23][24][25][26] As carbon materials are mainly composed of carbon and even can be made directly out of biomass, they are obviously "sustainable." The carbonaceous nanomaterials possess wide potential window and structural diversity, which can be active electrocatalysts for the oxygen reduction reaction and CO 2 reduction etc. [27,28] It is well accepted that nonmetal heteroatom doping (e.g., O, B, N, P, and S) can tailor the electronic structure of carbon atoms, which offers an effective method to promote the electrocatalytic performance. [29][30][31] Recent studies have proven that doping of B and N also enhances the NRR performances of carbon catalysts. [32][33][34] In this communication, we report that S-doped carbon nanosphere (S-CNS) acts as a suerb NRR catalyst for ambient N 2 -to-NH 3 conversion with excellent selectivity. In 0.1 m Na 2 SO 4 , the S-CNS achieves a large NH 3 yield of 19.07 µg h −1 mg −1 cat. and a high Faradic efficiency of 7.47% at −0.7 V versus reversible hydrogen electrode (RHE), much higher than those of undoped CNS (3.70 µg h −1 mg −1 cat. , 1.45%). Notably, this catalyst also demonstrates high electrochemical and structural stabilty.S-CNS was prepared via hydrothermal reaction followed by Ar annealing using glucose and benzyl disulfide as carbon and sulfur source, respectively. [35] Figure 1a shows the X-ray powder diffraction (XRD) pattern of S-CNS, and the diffraction peaks at 2θ = 23.8° and 44.0° are attributed to the (002) and (100) reflections of carbon, [36] respectively. Compared with CNS sample (Figure S1, Supporting Information), it can be clearly seen that the diffraction peaks of S-CNS become weaker and broader, confirming S has a great influence on the structure of carbon. [37] Figures 1b and S2 of the Supporting Information Industrial NH 3 synthesis mainly relies on the carbon-emitting Haber-Bosch process operating under severe conditions. Electrocatalytic N 2 to NH 3 fixation at ambient conditions is an attractive approach to reduce energy consumption and avoid direct carbon emission. In this communication, it is reported that the S-doped carbon nanosphere (S-CNS) acts as an efficient and stable nitrogen reduction reaction (NRR) catalyst for ambient N...

Monodispersed mesoporous phenolic polymer nanospheres with uniform diameters were prepared and used as the core for the further growth of core-shell mesoporous nanorattles. The hierarchical mesoporous nanospheres have a uniform diameter of 200 nm and dual-ordered mesopores of 3.1 and 5.8 nm. The hierarchical mesostructure and amphiphilicity of the hydrophobic carbon cores and hydrophilic silica shells lead to distinct benefits in multidrug combination therapy with cisplatin and paclitaxel for the treatment of human ovarian cancer, even drug-resistant strains.Mesoporous materials have diverse applications in catalysis, energy storage, separation, and biomedicine due to their unique properties attributed to high surface area, large pore volume, and regular large pore size. [1][2][3][4][5][6] Through the control of the growth and cooperation-assembly processes in solution phase, the morphology and particle size of the products can be modified. One important and exciting advance is to fabricate nanosized particles with ordered mesostructures through controlled sol-gel procedures in solution phase. [7][8][9][10][11][12][13][14][15][16] These mesostructured nanoparticles are attractive since they combine the advantages of the quantum effect of nanosized particles and the high surface area of mesostructures, which can lead to unconventional properties.

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In this work, we report the facile, environmentally friendly, room-temperature (RT) synthesis of porous CuO nanosheets and their application as a photocatalyst to degrade an organic pollutant/food dye using NaBH4 as the reducing agent in an aqueous medium. Ultrahigh-resolution field effect scanning electron microscopy images of CuO displayed a broken nanosheet-like (a length of ∼160 nm, a width of ∼65 nm) morphology, and the lattice strain was estimated to be ∼1.24 × 10–3 using the Williamson–Hall analysis of X-ray diffraction plots. Owing to the strong quantum size confinement effect, CuO nanosheets resulted in an optical energy band gap of ∼1.92 eV, measured using Tauc plots of the ultraviolet–visible (UV–vis) spectrum, resulting in excellent photocatalytic efficiency. The RT synthesized CuO catalyst showed a high Brunauer–Emmet–Teller surface area of 30.88 ± 0.2313 m2/g (a correlation coefficient of 0.99972) with an average Barrett–Joyner–Halenda pore size of ∼20.385 nm. The obtained porous CuO nanosheets exhibited a high crystallinity of 73.5% with a crystallite size of ∼12 nm and was applied as an efficient photocatalyst for degradation of the organic pollutant/food dye, Allura Red AC (AR) dye, as monitored by UV–vis spectrophotometric analysis and evidenced by a color change from red to colorless. From UV–vis spectra, CuO nanosheets exhibited an efficient and ultrafast photocatalytic degradation efficiency of ∼96.99% for the AR dye in an aqueous medium within 6 min at RT. According to the Langmuir–Hinshelwood model, photodegradation reaction kinetics followed a pseudo-first-order reaction with a rate constant of k = 0.524 min–1 and a half-life (t 1/2) of 2.5 min for AR dye degradation in the aqueous medium. The CuO nanosheets showed an outstanding recycling ability for AR degradation and would be highly favorable and an efficient catalyst due to the synergistic effect of high adsorption capability and photodegradation of the food dye.

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