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Modification of the environmentally-friendly non-metallic polymer semiconductor graphite carbon nitride (g-C3N4) has been a research hotspot in the field of photocatalysis, and is regarded as a pivotal solution to energy problems. Nevertheless, the bottlenecks of a slow carrier separation rate, limited visible light absorption and weak water reduction driving force have not been effectively solved due to uneven mass and heat transfers during high-temperature calcination; therefore, no carbon nitride photocatalysts with excellent properties can be provided. Recently, optimizing the modification with multiple methods has become an important research direction. To generate better photocatalysts, we propose a facile copolymerization strategy by combining doping and pore formation to inhibit the agglomeration and efficiently optimize the surface properties and external structure of the catalyst, thereby improving its photocatalytic performances. The amended g-C3N4 produces a broadened visible-light response, a larger surface area, and reformative separate efficiency of charge carriers. Thus, the effectively-modified g-C3N4 has enhanced H2 production, which is 6.3-fold greater than that of pristine carbon nitride.

This study focuses on the synthesis and characterization of Ag nanoparticle-decorated reduced graphene oxide (RGO) nanocomposites (Ag-RGO), which were obtained via a facile, green and efficient one-pot hydrothermal method. TEM results showed that the silver nanoparticles (20-50 nm) were uniformly attached onto RGO sheets with C/O ratio of 6.4 and 80% of sp2 carbon, obtained from XPS analysis. Compared with GO and RGO, the prepared Ag-RGO composites possessed significant antibacterial property; the minimum inhibitory concentration of Ag-RGO was just 31.25 μg/mL against Gram-positive bacteria S. aureus and Gram-negative bacteria E. coli. Particularly, the Ag-RGO nanocomposites released more Ag+ in acidic condition, promoting the produce of reactive oxygen species, which are acknowledged as disruption to the membrane integrity of the bacteria. Moreover, the Ag-RGO nanocomposites effectively dispersed and eliminated the maturely formed biofilm, showing superior advantages in responding to public health threats posed by biofilm-related infections.

Catalytic activity and target product selectivity are strongly correlated to the size, crystallographic phase, and morphology of nanoparticles. In this study, waste lignin from paper pulp industry is employed as the carbon source, which is modified with carboxyl groups at the molecular level to facilitate anchoring of metals, and a new type of carbon-based catalyst was obtained after carbonization. As a result, the size of the metal particles is effectively controlled by the chelation between -COO- and Fe3+. Furthermore, Fe/CM-CL with a particle size of 1.5-2.5 nm shows excellent catalytic performance, the conversion of carbon monoxide reaches 82.3%, and the selectivity of methane reaches 73.2%.

Metal-organic frameworks (MOFs)-derived catalysts exhibit highly-efficient hydrogen or oxygen evolution performance on water splitting. However, it is an urgent problem to construct bifunctional electrocatalysts for both hydrogen and oxygen evolution performance. Herein, we adopted Ag nanowires as templates to prepare one-dimensional Ag nanowire@ZIF-8@ZIF-67 precursors (1D AgNW@ZIF-8@ZIF-67). Through pyrolysis, AgNW@ZIF-8@ZIF-67 precursors transformed into nitrogen-doped carbon frameworks (NCF) embedded with zinc-cobalt (ZnCo) nanoparticles on the surface of Ag NWs (denoted as Ag@ZnCo/NCF nanohybrids). The nanohybrids were consisted of Ag NWs with good conductivity and ZnCo/NCF nanohybrids with rich accessible active sites. Benefiting from their large specific surface area, accessible active sites and synergistic effect among components, Ag@ZnCo/NCF nanohybrids exhibit lower overpotentials of 139 mV and 279 mV at the current density of 10 mA cm−2 for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline solution, severally. Compared with other catalysts, Ag@ZnCo/NCF nanohybrids possess smaller Tafel slope, indicating their higher catalytic activity. This work provides a new perspective for designing low-cost and highly efficient bifunctional electrocatalysts for overall water splitting.

Graphite carbon nitride (g-C3N4) is a fascinating 2D photocatalyst, but preparing ultrathin g-C3N4 with outstanding surface properties by a green and facile method is still a tremendous challenge. In this research, g-C3N4 nanosheets were modified through H2O2-assisted rapid thermal surface treatment. The rapid decomposition of H2O2 molecules on the surface greatly optimized the surface properties of the catalyst. Thus, the modified g-C3N4 nanosheets had more interfacial active sites and broader visible light absorption and showed the largest hydrogen evolution rate of 894.9 μmol g−1 h−1. Photoluminescence and electron spin resonance (ESR) assays showed that the modified photocatalyst accelerated charge transfer and thereby attained higher photocatalytic H2 generation efficiency. This research offers a new strategy to develop g-C3N4-based 2D photocatalysts for H2 preparation.

A facile method was proposed to prepare mesoporous AgPtPd nanotubes (M-AgPtPd NTs) alloy electrocatalysts. The M-AgPtPd NTs presented excellent electrocatalytic activity and robust durability for H2 evolution in 1.0 M KOH solutions. Specifically, the M-AgPtPd NTs achieved a significantly lower overpotential (19.6 mV) at the current density of 10 mA∙cm−2 compared with commercial Pt/C catalysts (31.6 mV). The M-AgPtPd NTs also displayed remarkable stability after 1000 cycles. This excellent catalytic activity of the M-AgPtPd NTs electrocatalysts can be ascribed to the trimetallic characteristics and the unique mesoporous structure.

Monometallic catalyst Pt/SAPO-11 was prepared by impregnation method. Bimetallic catalysts LaPt/SAPO-11 or CePt/SAPO-11 was prepared by sequential impregnation method. The catalysts were characterized by X-ray diffraction (XRD), nitrogen adsorption, temperature-programmed desorption of ammonia (NH3-TPD), and Fourier transform infrared spectroscopy (FT-IR) techniques. The results showed that with the addition of rare earths the BET surface areas, pore volume, the amount of Bronsted acid and the total acidity of catalysts decreased slightly. However, the additive addition could lead to an increase in the amount of Lewis acid. Meanwhile, the introduction of additive was feasible to promote the dispersity of Pt. In addition, the hydroisomerization of n-heptane over different catalysts was studied. Compared with Pt/SAPO-11, LaPt/SAPO-11 or CePt/SAPO-11 showed higher catalytic activity and yield of i-C7 due to its higher Pt dispersion.

In the previous research, the effects of different addition time and amount of printed circuit boards (PCBs) on cells growth and metals recovery in separated and mixed culture of Acidithiobacillus thiooxidans and Acidithiobacillus ferrooxidans were investigated. This paper aimed to optimize mixed culture of both acidophiles for maximizing PCBs addition amounts and copper leaching percentage simultaneously. Initially, influences of inoculums ratio between two acidophiles on their cells growth were studied. Then, initial medium pH and concentrations of FeSO4 · 7H2O and elemental sulfur (S(0)) were optimized by response surface methodology (RSM) to improve copper recovery. Finally, multiple-point PCBs addition was tested to determine maximal amounts. Results showed that with initial inoculums ratio (Af:At) 1:2, pH 1.56, FeSO4 · 7H2O and S(0) at 16.88 and 5.44 g/L, and PCBs addition 28.8 g/L, copper recovery reached 92.6% after 240 h cultivation. It was indicated that copper could be efficiently leached out from increased PCBs addition amount and FeSO4 · 7H2O was remarkably reduced from 22.1 to 16.88 g/L.