Program for Integration of MQ 135(CO2) and DHT 11(Temp, Humidity) Sensors

Here I attached my code for the integration of two sensors (MQ135 & DHT 11) with Arduino UNO. In an LCD display, I didn’t get the output. If someone corrects the code, it will be helpful for me. Thank you.

#include <LiquidCrystal.h>
int sensorValue;
const int rs = 4, en = 5, d4 = 0, d5 = 1, d6 = 2, d7 = 3;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);

LiquidCrystal lcd1(rs, en, d4, d5, d6, d7);
byte degree_symbol[8] = 
              {
                0b00111,
                0b00101,
                0b00111,
                0b00000,
                0b00000,
                0b00000,
                0b00000,
                0b00000
              };
int gate=11; 
volatile unsigned long duration=0;
unsigned char i[5];
unsigned int j[40];
unsigned char value=0;
unsigned answer=0;
int z=0;
int b=1;


void setup(){  
  lcd.begin(16, 2);
  Serial.begin(9600);                            // sets the serial port to 9600

  lcd1.begin(16, 2);
  lcd1.print("Temp = ");
  lcd1.setCursor(0,1);
  lcd1.print("Humidity = ");
  lcd1.createChar(1, degree_symbol);
  lcd1.setCursor(9,0);
  lcd1.write(1);
  lcd1.print("C");
  lcd1.setCursor(13,1);
  lcd1.print("%");

 }
void loop()
{

while(1){
  sensorValue = analogRead(0);       // read analog input pin 0
  Serial.print("AirQua=");
  Serial.print(sensorValue, DEC);               // prints the value read
  Serial.println(" PPM");
  lcd.setCursor(0,0);
  lcd.print("ArQ=");
  lcd.print(sensorValue,DEC);
  lcd.print(" PPM");
  lcd.println("       "); 
  lcd.print("  ");
  delay(1000);                                   // wait 10000ms for next reading


//code for second set here
  delay(1000);
  pinMode(gate,OUTPUT);
  digitalWrite(gate,LOW);
  delay(20);
  digitalWrite(gate,HIGH);
  pinMode(gate,INPUT_PULLUP);//by default it will become high due to internal pull up
 // delayMicroseconds(40);

  
  duration=pulseIn(gate, LOW);
  if(duration <= 84 && duration >= 72)
  {
      while(1)
      {
        duration=pulseIn(gate, HIGH);
        
        if(duration <= 26 && duration >= 20){
        value=0;}
        
        else if(duration <= 74 && duration >= 65){
        value=1;}
        
        else if(z==40){
        break;}
        
        i[z/8]|=value<<(7- (z%8));
        j[z]=value;
        z++;
      }
    }
answer=i[0]+i[1]+i[2]+i[3];

if(answer==i[4] && answer!=0)
{
lcd1.setCursor(7,0);
lcd1.print(i[2]);
lcd1.setCursor(11,1);
lcd1.print(i[0]);
}

z=0;
i[0]=i[1]=i[2]=i[3]=i[4]=0;
 }


  }