Visible light response is as important as energy band potential for photocatalytic water splitting. In this work, upconversion CeF3 nanoparticles are developed by O and N doping. The contents and species of O and N regulated by various temperatures act on the large-scale regulation of defects and band structures distinctly, which can suppress the recombination of photogenerated carriers. O,N-CeF3-160 nanoparticles establish the most suitable defects and electronic structure in all O,N-CeF3 nanoparticles. It exhibits the optimal oxygen evolution rates up to 1277 μmol g–1 h–1, whose apparent quantum yield (AQY) is up to 53.09% at 550 nm. The photoluminescence (PL) spectra and density of state (DOS) illustration elucidate the internal reason for the distinct photocatalysis activity. Defects are just as important as band structure in the modification of O,N-codoped CeF3 upconversion nanoparticles. This work provides the approach to regulate CeF3 upconversion materials to achieve better photoactivity under visible light.

A facile and feasible method was innovatively evolved to in-situ prepare g-C 3 N 4 /TiO 2 heterojunctions through a high concentration absorption process, to satisfy the exigent requirements of an e cient, lowcost and environmental-friendly photocatalyst for massive antibiotic e uent treatment. This synthesis method was much easier and more rapid than the traditional routes, which can be primarily depicted as follows: the nitrogen precursors were uniformly dispersed on the amorphous hydrolysis product of titanium precursors (titanic acid or metatitanic acid) driven by a concentration gradient, and then, affording the heterostructure of granular TiO 2 coupled with lamellar g-C 3 N 4 through a calcination process. The effects of the one-step synthesis on the characteristics of g-C 3 N 4 /TiO 2 nanocomposites were investigated by XRD, HRTEM, XPS, UV-vis DRS and PL, and the results demonstrated that the nanocomposites exhibited a well-de ned micromorphology and enhanced photoabsorption capacity. For the degradation of tetracycline hydrochloride, the g-C 3 N 4 /TiO 2 heterojunction displayed remarkably elevated photocatalytic activity over bare g-C 3 N 4 and commercial TiO 2 under simulated sunlight and visible light. The sample with 4 g of urea content was optimal, with photodegradation e ciencies 3.9 and 2 times higher than those of pure g-C 3 N 4 and TiO 2 respectively. Besides, photodegradation pathways based on the role of active species •O 2 − and •OH were identi ed by the trapping experiments, indicating that the substantial increase in photocatalytic e ciency can be credited to the construction of direct Zscheme heterojunctions. This work has provided a novel in-situ synthesis approach to the heterostructure, which would open up new horizons for the rational design and the wide-scale application of highperformance photocatalysts for the photodegradation of antibiotic-based pollutants.

The rational design and synthesis of a highly efficient and cost-effective electrocatalyst for hydrogen evolution reaction (HER) are of great importance for the efficient generation of sustainable energy. Herein, amorphous/crystalline heterophase Ni–Mo–O/Cu (denoted as a/c Ni–Mo–O/Cu) was synthesized by a one-pot electrodeposition method. Thanks to the introduction of metallic Cu and the formation of amorphous Ni–Mo–O, the prepared electrocatalyst exhibits favorable conductivity and abundant active sites, which are favorable to the HER progress. Moreover, the interfaces consisting of Cu and Ni–Mo–O show electron transfers between these components, which might modify the absorption/desorption energy of H atoms, thus accelerating HER activity. As expected, the prepared a/c Ni–Mo–O/Cu possesses excellent HER performance, which affords an ultralow overpotential of 34.8 mV at 10 mA cm–2, comparable to that of 20 wt % Pt/C (35.0 mV), and remarkable stability under alkaline conditions.

A facile and feasible method was innovatively evolved to in-situ prepare g-C3N4/TiO2 heterojunctions through a high concentration absorption process, to satisfy the exigent requirements of an efficient, low-cost and environmental-friendly photocatalyst for massive antibiotic effluent treatment. This synthesis method was much easier and more rapid than the traditional routes, which can be primarily depicted as follows: the nitrogen precursors were uniformly dispersed on the amorphous hydrolysis product of titanium precursors (titanic acid or metatitanic acid) driven by a concentration gradient, and then, affording the heterostructure of granular TiO2 coupled with lamellar g-C3N4 through a calcination process. The effects of the one-step synthesis on the characteristics of g-C3N4/TiO2 nanocomposites were investigated by XRD, HRTEM, XPS, UV-vis DRS and PL, and the results demonstrated that the nanocomposites exhibited a well-defined micromorphology and enhanced photoabsorption capacity. For the degradation of tetracycline hydrochloride, the g-C3N4/TiO2 heterojunction displayed remarkably elevated photocatalytic activity over bare g-C3N4 and commercial TiO2 under simulated sunlight and visible light. The sample with 4 g of urea content was optimal, with photodegradation efficiencies 3.9 and 2 times higher than those of pure g-C3N4 and TiO2 respectively. Besides, photodegradation pathways based on the role of active species •O2− and •OH were identified by the trapping experiments, indicating that the substantial increase in photocatalytic efficiency can be credited to the construction of direct Z-scheme heterojunctions. This work has provided a novel in-situ synthesis approach to the heterostructure, which would open up new horizons for the rational design and the wide-scale application of high-performance photocatalysts for the photodegradation of antibiotic-based pollutants.

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