Enhanced photo-reduction performance of CuInS2 for aqueous Cr(VI) via facile combining with Bi2S3: a direct Z-scheme mechanism

Construction of Cu7S4@CuCo2O4 Yolk–Shell Microspheres Composite and Elucidation of Its Enhanced Photocatalytic Activity, Mechanism, and Pathway for Carbamazepine Degradation

“…First, we noticed the diffraction peaks (and their corresponding planes) of CS located at 2θ of 31.2° (18,2,1), 34.1° (20,0,1), 37.9° (10,0,3), 46.8° (0,16,0), and 48.9° (886) matched well the CS monoclinic phase (JCPDS no: 23-0958). [24] Similarly, the diffraction peaks (and their corresponding planes) of CCO located at 2θ of 31.25° (220), 36.96° (311), 38.63° (222), 44.68° (400), 59.66° (511), and 65.25° (440) matched well the characteristic peaks of the spinel lattice (JCPDS No 71-0816) (Figure 1a). [25] For the CS/CCO composites, all the peaks also matched the standard patterns of the CS and CCO, confirming that their formation and the growth of CS did not alter their respective crystal structures.…”

“…Based on the aforementioned results, we could elucidate the photocatalytic oxidation mechanism of CS/CCO heterostructures here (Figure 9d): a) when the CS contacted CCO, their bands aligned well, forming the CS/CCO heterostructures matched the direct Z‐scheme photocatalytic heterostructure, b) the photogenerated electrons from the CS and CCO were excited from VB to CB under light irradiation, c) due to the Coulombic interaction, these photogenerated electrons in the CB of CCO could readily recombine the photogenerated holes in the VB of CS at the heterojunction interface, thus boosting the separation of the electrons on CB and holes on the VB of CCO and CS, respectively, d) the electrons on CB of CS could reduce the O 2 to ·O− 2 radicals due to the reduction potential of ·O− 2 (−0.33 V vs NHE) was more positive than the E CB of CS (−0.803 V), [ 55,56 ] (e) the holes in the VB of CCO (1.747 V vs NHE) could directly degrade pollutants given its more negative oxidation potentials than H 2 O/·OH (2.38 V vs NHE), and (f) therefore successfully oxidized and degraded CBZ to smaller molecule products. [ 57–59 ]…”

“…[54] Based on the aforementioned results, we could elucidate the photocatalytic oxidation mechanism of CS/CCO heterostructures here (Figure 9d potential of •O− 2 (−0.33 V vs NHE) was more positive than the E CB of CS (−0.803 V), [55,56] (e) the holes in the VB of CCO (1.747 V vs NHE) could directly degrade pollutants given its more negative oxidation potentials than H 2 O/•OH (2.38 V vs NHE), and (f) therefore successfully oxidized and degraded CBZ to smaller molecule products. [57][58][59]…”

Development of Z-scheme bimetallic tungstate-supported nitrogen deficient g-C3N4heterojunction for the treatment of refractory pharmaceutical pollutants

“…CB and VB potentials for ND-GCN, NCW, and CZW nanomaterials were predicted using the Mulliken electronegativity theory and Mott Schottky investigations. The following formula can be used to obtain the Mulliken electronegativity ( χ ) of compound: 47 χ ( X x Y y Z z ) = ( χ ( X ) x χ ( Y ) y χ ( Z ) z ) 1/( x + y + z ) ,where x , y , and z represent the total number of X , Y , and Z atoms in an X x Y y Z z material; and χ ( X ), χ ( Y ), and χ ( Z ) represent the absolute electronegativity of the atoms. The Mulliken definition states that the absolute electronegativity of an atom is equal to the geometric mean of its electron affinity ( A ) and its first ionization energy ( I ).…”

Interfacial S–O bonds specifically boost Z-scheme charge separation in a CuInS2/In2O3 heterojunction for efficient photocatalytic activity

“…24 Recently, copper indium disulfide (CuInS 2 ), a ternary chalcogenide semiconductor, has shown great potential in photocatalysis due to its narrow band energy (∼1.8 eV) and high optical absorption coefficient ( α > 10 5 cm −1 ). 25,26 Furthermore, the CuInS 2 possesses a theoretically suitable band structures and Fermi levels with those of In 2 O 3 , 27,28 which makes them prospective candidates for constructing a Z-scheme heterostructure. However, to the best of our knowledge, very few reports currently focus on the assembling of such CuInS 2 /In 2 O 3 composite to achieve a promoted photocatalytic activity.…”