Synthesis and photocatalytic hydrogen production activity of the Ni-CH_3CH_2NH_2/H_(1.78)Sr_(0.78)Bi_(0.22)Nb_2O_7 hybrid layered perovskite

The nickel‐based complex Ni‐CH3CH2NH2‐intercalated niobate layered perovskite Ni‐CH3CH2NH2/H1.78Sr0.78Bi0.22Nb2O7was synthesized via a facile in situ chemical reaction method.Using ultrathin H1.78Sr0.78Bi0.22Nb2O7nanosheets and nickel acetate as precursors.The composition,structure,photophysical properties,and photocatalytic activity for H2production of Ni‐CH3CH2NH2/H1.78Sr0.78Bi0.22Nb2O7were studied systematically.The photocatalyst loaded with0.5wt%Ni exhibited the highest H2evolution rate of372.67μmo/h.This was0.54times higher than the activity of the H1.78Sr0.78Bi0.22Nb2O7nanosheets.The activity of the optimized Ni‐CH3CH2NH2/H1.78Sr0.78Bi0.22Nb2O7was comparable to that of the Pt‐loaded sample under the same reaction conditions.The photocatalytic activity of the Ni‐CH3CH2NH2/H1.78Sr0.78Bi0.22Nb2O7was mainly attributed to the excellent separation of photogenerated carriers,after formation of the intercalated complex Ni‐CH3CH2NH2.This study provides a facile strategy to synthesize a non‐precious metal‐loaded photocatalyst for H2production.

Enhanced photocatalytic hydrogen evolution along with byproducts suppressing over Z-scheme CdxZn1-xS/Au/g-C3N4 photocatalysts under visible light

Inspired by natural photosynthesis, a new series of Z-scheme Cd_xZn_(1-x)S/Au/g-C_3N_4 photocatalysts were synthesized via depositing Au particles on g-C_3N_4, followed by anchoring CdxZn_(1-x)S solid solution on the pre-formed Au/g-C_3N_4 for photocatalytic hydrogen evolution. Their structure, morphology and optical property were investigated in detail. Photocatalytic activities of the developed photocatalysts for water splitting were evaluated under visible-light irradiation(k > 420 nm) using glucose as electron donor.The highest hydrogen evolution rate of 123 lmol g^(-1)h^(-1)is achieved by Cd_(0.8Z)n_(0.2)S/Au/g-C_3N_4, which is 52.2 and 8.63 times higher than that of Au/g-C_3N_4 and Cd S/Au/g-C_3N_4, respectively. The results of photoluminescence spectra, photoelectrochemical and time-resolved photoluminescence spectra indicate that the improved photocatalytic activities for Cd_xZn_(1-x)S/Au/g-C_3N_4 are due to the efficient separation of photogenerated carriers. In addition, it is noteworthy that the undesired byproducts CO and CO_2 are greatly reduced by introducing CdxZn_(1-x)S over Au/g-C_3N_4 surface. In the photocatalytic process, gluconic acid originated from the reaction of photogenerated hydroxyl radical with glucose plays a vital role on suppressing the formation of the gas byproducts. The present work will provide a new strategy to design Z-scheme photocatalysts with enhanced efficiency for water splitting along with suppressing the byproducts.

Assessing non-point source pollution in an apple-dominant basin and associated best fertilizer management based on SWAT modeling

Investigating the impact of apple-dominated areas on nitrogen(N)and phosphorus(P)losses at a basin scale was essential for the sustainable development of apple industry in China.This study conducted a survey on fertilizer application and built a Soil and Water Assessment Tool(SWAT)model to quantita-tively analyze the N and P losses in the Qixia apple-dominated area.Additionally,the decreases in N and P losses through adjusting the fertilizer application modes were evaluated.Results showed that average N and P losses in the Wulong River Basin(WRB)were 44.4 and 0.365 kg ha^(-1)in 2011-2017,respectively,and apple orchards accounted for 733%and 51.4%of the total N and P losses in the basin.Under nine fertilizer scheduling scenarios,three fertilizer schedule scenarios,automatic fertilizer application(S-AUTO),"one shot"mode(S1),and regulated fertilizer application(S-BSD),had the lowest N and P losses in apple orchards.The decreases in N loss ranged from 20.6%to 26.1%at the subbasin scale and 14.8%-30.7%at the basin outlet when applying the S-AUTO,S1,and S-BSD fertilizer application modes in Qixia apple orchards and all apple orchards in the WRB.The reductions in P loss varied from 22.0%to 46.1%at the subbasin scale and 14.6%-25.6%at the basin outlet.In orchard-dominated basin,N and P losses can be effectively reduced by optimizing the orchard fertilizer scheduling strategies.